METALLICS
IRON
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A lustrous, ductile, malleable,
silver-gray metal.
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4th most common element in the earth’s
crust.
·
2nd most abundant metallic element.
PRINCIPAL
IRON MINERALS: Hematite( Varieties:
Red Ochre – Red Earthy luster, Specularite- Metallic luster) Magnetite (
Lodestone), Limonite, Goethite, Siderite.
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Philippine
iron deposits are classified into:
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A) SKARN
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Limestone
or calcareous sediments are intruded by a younger intermediate to acidic
pluton
MOST
IMPORTANT IRON DEPOSITS IN THE PHILIPPINES
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B) MAGNETITE
SAND
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Deposit
type consists of magnetite concentrations in beach and alluvial sand.
Batas Pambansa Blg. 265 – “ An Act
Prohibiting the Extraction of Gravel and Sand from Beaches and Providing
Penalties Thereof” which was approved on Nov. 13, 1982.
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C) LATERITE
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The
deposits are of two types: nickeliferous and aluminous.
- ultramafic
rocks (e.g., dunite and peridotite) are nickeliferous as these rocks
contain significant amounts of nickel that develop into silicate nickel
ore (garnierite)
- mafic
rocks (e.g., gabbro and basalt) are high in alumina (Al2O3) bauxite or bauxitic clay forms.
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d) sedimentary
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Sedimentary
iron deposits are in the form of layers of hematite and/or magnetite
interbedded with sediments.
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e) bog
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Occur
in small low-grade deposits with much manganese, phosphorus, water, clay, and
other impurities.
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f) spring
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Originated
as spring emanations in Quaternary volcanic terranes.
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LOCATION
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OPERATOR
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HOST ROCK
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AGE
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SKARN
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a. Larap Iron-Copper-Molybdenum skarn deposit
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Larap, Jose Panganiban,
Camarines Norte
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The oldest rock suite and host to
iron-base metal mineralization consists of the metamorphosed interbedded marls,
calcareous shales, arkoses,
graywackes, sandstones and conglomerates of the Early Miocene age
Universal Formation or Tumbaga Formation intruded by swarms of granodioritic
to monzonitic dikes related to a diorite (Tamisan Diorite)stock sw of the ore
body.
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Late Miocene age
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b. Sta.Ines iron-skarn deposit
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Santa Ines,
Antipolo, Rizal
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Santa Ines Iron and Steel Corporation
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Santa
Ines Diorite intruded limestone and clastic rocks
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Late
Eocece to Middle Miocene
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c. Lamin iron-skarn deposit
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Lammin, Carasi,
Ilocos Norte
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Ilocandia Iron and Smelting Incorporated
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Diorite and quartz diorite stocks
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Oligocene age
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MAGNETITE SAND
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Sta. Cruz and Agoo magnetite sand deposits
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Sta. Cruz to Tagudin, Ilocos Sur and
Agoo,
La Union
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The beach sand is fine to
medium-grained. Magnetite occurs either as grains disseminated with other
alluvial minerals in the sand or within distinct layers that are
subcentimeter to 2 cm thick. These coastal areas are underlain by clastic
sedimentary rocks of Upper Miocene – Pleistocene age.
Magnetite comes from the erosion of
older rock units in the Central Cordillera.
Primary
mineral: Titanomagnetite
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Younger than Upper Miocene –
Pleistocene age.
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LATERITE IRON
DEPOSITS
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Laterite iron deposits of the Surigao
Mineral Reservations
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The reservation comprises the central
eastern portion of Surigao peninsula (Parcel I) in northeastern Mindanao;
southern Dinagat, Nonoc, Hinatuan and Masepelid islands and lesser isles
(Parcel II); northern Dinagat island (Parcel III); and Siargao and Bucas
Grande islands (Parcel IV)
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The laterite iron deposits are residual
products of chemical weathering of serpentinized ultramafic rocks.
Limonite
is the chief constituent of the laterite iron ore while hematite and
magnetite occurs in subordinate amounts.
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Pleistocene
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SEDIMENTARY
BEDDED IRON DEPOSIT
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Camalaniugan
Sedimentary bedded iron deposit
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Geographical name: Bgy. .Camalaniugan,
Aparri, Cagayan (10 km south of Aparri Poblacion, Cagayan)
Central geographic coordinates: 18°18’N,
121°37’E
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The deposit formed within a structural
basin that probably ponded into a lake. Iron supplied into this basin
originated from the chemical weathering of surrounding rocks, which shows
evidence of pyritization probably brought about by dioritic intrusions.
Principal Ore: Hematite and Limonite
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SEDIMENTARY
BOG IRON DEPOSIT
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Taan
sedimentary bog iron deposit
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Geographical description: The deposit
lies at the southern sector of Nueva Vizcaya near the provincial boundary of
Quezon and Nueva Ecija. It is within the interior highland of the Sierra
Madre mountains.
Central geographic coordinates: 15°38’N,
121°19’E
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The upper section of the Pliocene Ilagan
Sandstone hosts the iron deposit. Overlying this unit in probable
unconformity is a flat-lying, poorly consolidated conglomerate, probably
equivalent to the Pleistocene Alat Conglomerate
Principal Ore: Hematite and Magnetite
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Nickel
·
A
silvery white, magnetic metallic element used chiefly in making alloys.
·
A common
by-product of nickel laterite deposits is cobalt.
·
22nd in
natural abundance among elements in crustal rock.
Pricnipal
Ore: Garnierite, Millerite, Niccolite, Pentlandite, Pyrrhotite
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CLASSIFICATION
OFDEPOSIT
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NICKEL LATERITE
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derived from the weathering of underlying
ultramafic rocks found along the ophiolite belts of the country form the bulk
of nickel deposits.
Localities: Surigao, Palawan and Samar
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NICKEL SULFIDES
Magmatic Nickel Sulfide Deposit
Hydrothermal
Nickel Sulfide deposit
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Magmatic nickel sulfide is closely associated
with chromitites and platinum group elements (PGE).
Localities: Acoje, Sta. Cruz, Zambales
occurs in narrow silicified zones in serpentinite
rock and in rocks immediately adjacent to it. Known deposits are believed to
be epithermal (i.e., formed at shallow depths).
Localities: Leyte and Ilocos Norte
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Nickel
laterite
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LOCATION
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OPERATOR
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HOST ROCK
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AGE
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Rio Tub nickel laterite deposit
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Barangay Rio Tuba,
Bataraza, Palawan
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Rio Tuba
Nickel Corporation
(RTNMC)
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Ultramafic Member
of thePalawan Ophiolite, consisting of the Mt. Beaufort ultramafics and the Espina
Formation
The in-situ weathering of the Mt. Beaufort
ultramafics resulted in the concentration and enrichment of nickel and cobalt
in the preserved laterite (soil) profile.
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Late Cretaceous
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Hinatuan Island
nickel laterite
deposit
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Geographical name: Tagaba-an, Nonoc Island,
Surigao del Norte
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Hinatuan Mining
Corporation
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ultramafic rock consists predominantly of harzburgite
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Nonoc Island
nickel laterite
deposit
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Nonoc
Island, Surigao
del Norte
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Philnico Mining and
Industrial Corporation
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Nickeliferous
laterites are developed on the ultramafic rocks.
Limonite
Type
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Adlay-Cadianao-
Tandawa (ACT)
Project
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Carrascal,
Surigao del Sur
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QNI Ltd.
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The
nickel laterites are developed on the ultramafic rocks bordering the eastern
portions of Surigao del Norte
The
main nickel ore is limonite and garnierite
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MAGMATIC NICKEL
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Acoje magmatic nickel sulfide deposit
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Sitio Pasicar, Sta. Cruz, Zambales
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Acoje Mining Corp.
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The nickel sulfide lenses are hosted primarily by
the black dunite facies.
Nickel
sulfide mineralization is dominated by pentlandite although some occurrence
of heazlewoodite and godlevskite were also noted.
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EPITHERMAL NICKEL
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Jaro deposit
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Minulho, Jaro Leyte
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Nickel sulfides occur along silicified shear
zones in the serpentinite as individual grains and as colloform bands
The mineralization is being linked with
Pliocene-Pleistocene volcanism.
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Pliocene-Pleistocene
volcanism
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Limonite zone. The
limonite zone, as the term implies, is composed predominantly of iron clay
minerals. It is usually capped by reddish-brown soil with low nickel
content. Most often, this capping,
termed as overburden in mining parlance, is low in nickel but rich in iron as
manifested by the presence of iron pisolites or hard caps. As this material
progresses downward, the color usually turns into various shades of yellow and
brown (Zone 2, the accumulation zone). It is still rich in iron but the nickel
values are now relatively higher than the upper portion. The limonite zone
exhibits plasticity and highly porous. Slightly weathered boulders of the
bedrock most often appear in the lower portion of the limonite zone.
Saprolite zone. The
contact between the limonite and the saprolite (Zone 4) may be gradational or
sharp. Depending on the intensity of weathering and laterite development, the
saprolite may have variable thickness even in one confined area. This thickness
range from less than a meter to more than 8 meters. The saprolite is colored
with various shades of green mixed with hues of yellow and brown. It turns into
various shades of blue, gray to black as it approaches the bedrock. The iron
content becomes sharply and significantly less than in the limonite zone while
the magnesium content progressively becomes richer at depth. The higher ore
grade is believed to be due to the downward migration of nickel which
eventually settles along the numerous cracks in the saprolite. The ubiquitous
green coatings along fractures are often due to garnierite, a high grade
Chromium
- 21st in natural abundance among the elements
in crustal rocks.
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CLASSIFICATION
OF PRIMARY PODIFORM (Orthomagmatic) CHROMITE DEPOSIT
chrome to iron ratio (Cr:Fe)
metallurgical (2.4-3.2:1)
refractory (1.8-2.3:1)
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PRIMARY PODIFORM (Orthomagmatic) CHROMITE
DEPOSITS
The chromite deposits generally occur within the
ultramafic portions of ophiolite complexes. Peridotite rocks that host the
mineralization are harzburgite, dunite, and cumulate ultramafic-mafic layers
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OPHIOLITE
BELTS (Alpine- Type)
1) Zambales Ophiolite
2) Casiguran Ophiolite
3) Angat Ophiolite
4) Eastern Bicol-Eastern Mindanao
Ophiolite
5) Western Bicol-Eastern Leyte
Ophiolite
6) Central Mindanao
Ophiolite
7) Antique Ophiolite
8) Zamboanga-Sulu Ophiolite
9) Palawan
Ophiolite.
A complete ophiolite consists of a continuous
sequence from top to bottom of metamorphic peridotite, cumulate peridotite,
pyroxenite, dunite, chert, spilite, and conformable pelagic sediments that
are collectively thought to represent oceanic crust and upper mantle
material.
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RESIDUAL AND TRANSPORTED CHROMITE DEPOSITS
The chromite deposits in laterite and
alluvial/beach placer sands are associated with ultramafic exposures.
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LOCATION
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OPERATOR
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GEOLOGY
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AGE
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Acoje orthomagmatic
podiform chromite
deposit
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Pascal, Sta.
Cruz,
Zambales;
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Acoje Mining Corp.
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Metallurgical chromite mineralization at Acoje
generally occurs as pods, and lenses within the dunite horizon and the basal cumulate
mafic sequence.
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Coto orthomagmatic
podiform chromite
deposit
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Baloganan, Masinloc,
Zambales
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Consolidated
Mines, Inc. and operated by Benguet
Corporation
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The deposit occurs within the Coto Block
of the Zambales Ophiolite Complex.
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Krominco orthomagmatic
stratiform deposits
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Dinagat Is.,
Surigao del Norte
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Krominco, Incorporated
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The chromitite bodies appear as pseudobedded
deposits associated with the dunite unit of the Dinagat ophiolite
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Samar lateritic (residual) chromite deposit
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Llorente, Hernani and McArthur, Samar
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Co-owned by Pacific
Shore Mining and Rio
Chico Mining corporations
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Chromite
occurs mainly as (i) residual concentrations in laterites, (ii) sand as
transported alluvial lateritic material deposited in flat areas near the
shore and in karsted limestone areas, and (iii) primary chromite as densely
disseminated bands and massive lenses in serpenti-nized bedrock.
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Batang-Batang alluvial chromite and chromite sand
deposit
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Narra, Palawan,
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Philcrome
Mining
Corporation
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Quaternary beach sediments adjacent to the
exposed ultramfaic complex of the Palawan Ophiolite
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MANGANESE
- a silver-gray, brittle metallic element used
principally in making alloys
- 12th in abundance among elements in the
earth's crust.
ORE: Rhodocrosite, Franklinite, Psilomelane/
Romanechite, Hausmannite, Braunite, Rhodonite, Alabandite, Manganite
Ukraine
is the world’s leading producer of high-grade
manganese ore, followed by Georgia, South
Africa, Brazil, and Gabon.
Most of the manganese deposits of commercial
importance are confined in a belt
between 45º north latitude and 25º south
latitude.
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CLASSIFICATION
Primary ( Volcanic-sedimentary) Manganese
Deposits
Primary manganese deposits of
volcanic-sedimentary origin are those deposits associated with : a) submarine
volcanic rocks and chert ; b) tuff and tuffaceous sedimentary rocks and some
chert ; and c) chert only.
Secondary (Residual) Manganese Deposits
These deposits are formed by the weathering and
reconcentration of manganese from primary bedded manganese oxides.
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LOCATION
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OPERATOR
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GEOLOGY
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AGE
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Primary sedimentary and epigenetic deposits and
secondary(residual)
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Anda Peninsula
, Bohol
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New Frontier Mines, Inc.
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Manganese
ore mineralization at the Anda Peninsula offers a low grade residual deposits
that consist of fined-grained manganese oxide particles that range in size
from 0.2 to 5 centimeters in size containing an average of 20 percent
manganese.
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Sedimentary
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Madulag, Baler, Aurora
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Central Mining Corporation.
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The manganese deposits appear to consist of
tabular to lenticular through
pockety bodies ranging from a few centimeters to about 3.5 meters
thick.
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Primary sedimentary deposit
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Coron , Busuanga
Island, Palawan
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Jordan Mining and Industrial Corporation
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Manganese occurs as intertonguing layers and/or
bedded with chert and jasper.
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Residual type
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Barangay Camangue Lolloken, Municipality of Enrique Villanueva, Siquijor
Island, Negros Oriental
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Badillo Mining
Corporation
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This
residual concentration of manganese ore consists of 1 – 2 meters thick sandstones impregnated
with manganese oxide of the Basac Formation. The ore occurs on the surface as
beds, stringers, scattered pebbles and boulders.
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Sedimentary and residual deposit
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Bawang,Jiabong , Western Samar
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The sedimentary deposit consists of tabular to
lenticular body in tuffaceous limestone and chert of Cretaceous formation.
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Copper
- a brownish-red metallic element,
- 25th most abundant element in crustal rocks.
Principal
Ore: Chalcopyrite and Bornite, Chalcocite, Covellite, Malachite,Azurite and
Chrysocolla.
In
the Philippines, the principal sources of copper are porphyry copper deposits
associated with dioritic to quartz dioritic and granodioritic stocks and
batholiths occurring in major arcs of the Philippines.
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Porphyry
Copper
- dioritic to quartz dioritic and
granodioritic stocks and batholiths
They are distributed over a wide age range:
Cretaceous in Cebu, Oligocene in Nueva Vizcaya and
southeastern Negros, Late Miocene to Pliocene in the Luzon Central
Cordillera.
Epithermal/mesothermal
vein-type
- Late Miocene to Pliocene.
VMS
Kuroko-Type-
These are strata-bound polymetallic mineral
deposits genetically related to submarine acid volcanic activity
Cyprus- Type- The Cyprus-type refers
to the massive sulfide base metal sulfide ores associated with rocks of
mafic-ultramafic association of ophiolitic affinity
Besshi- Type- The description for the Besshi- or
Kieslager-type copper deposits is that of stratabound massive cupriferous
iron sulfide deposits, bed-like or lenticular in form, that lie conformably
in crystalline schists (Kanehira and Tatsumi, 1970). It is now recognized,
however, that these types of deposits are simply metamorphosed VMS deposits,
of either the Kuroko or Cyprus types
Vein- Type
Copper
volcanic-hosted Cu-As-Sb veins – HS veins
mafic/ultramafic-hosted
chalcopyrite-pyrrhotitepyrite-quartz veins
Copper Skarn-
Skarns are rocks consisting of Ca-Fe-Mg-Mn
silicates formed by the replacement of carbonate-bearing rocks accompanied by
regional or contact metamorphism and metasomatism, in response to the
emplacement of intrusives of varying compositions.
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PORPHYRY
COPPER
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LOCATION
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OPERATOR
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HOST ROCK
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AGE
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Sto. Tomas II
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Padcal, Tuba, Benguet
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Philex Mining Corporation
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hornblende quartz
diorite porphyry,
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Far Southeast
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Mankayan, Beguet
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Lepanto Consolidated
Mining
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Quartz diorite
porphyry stock
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Dinkidi
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Didipio, Kasibu, Nueva
Vizcaya
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Climax Mining Corporation
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dark Diorite
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Middle Miocene.
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San Antonio
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Sta.Cruz, Marinduque
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Marcopper Mining
Corporation
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granodioritic to quartz dioritic
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Carmen
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Brgys.
Toledo and
Biga, Toledo
City, Cebu
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Atlas Consolidated
Mining and Development
Corporation
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Lutopandiorite and intruded rocks.
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Kingking
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Lawaan,PantuKan,
Compostela Valley
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(NADECOR)
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diorite intrusive complex
partly by the intruded
metamorphosed volcanics
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Miocene diorite intrusives.
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Batong-buhay
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Pasil, Kalinga
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diorite body
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Boyungan
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Silangan Mindanao
Mining Corporation
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VMS
DEPOSITS
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LOCATION
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OPERATOR
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HOST ROCK
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AGE
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Ungay-Malobago- Besshi Type
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Pacolbon,Rapu-Rapu,
Albay Prov
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Rapu-Rapu Minerals Inc.
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altered dacitic volcanic layers that are closely
associated with intercalated quartzo-feldspathic (felsic)
schists.
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Middle to Late Cretaceous.
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Hixbar- Besshi
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Karog-kog, Rapu-Rapu, Albay Province
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Hixbar Gold Mining Co. /Nielsen and Company
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same
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same
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Canatuan
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Sitio Canatuan, Bgy. Tabayo, Siocon,
Zamboanga del Norte
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TVI Resource
Development
(Philippines), Inc.
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Tungauan schists
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Bagacay
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Hinabangan, Samar
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Sulat
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Lonoy and Bonot, Sulat, Eastern Samar
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Trident Mining and
Industrial Corp.
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dacitic rocks
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HIGH
SULFIDATION EPITHERMAL
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Tampakan
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Tampakan, South
Cotabato
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Sagittarius Mines
Incorporated
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Mineralization in the area is hosted by a
sequence of intermediate to alkali volcanics and subvolcanics, which are
intruded by rocks of wide range compositions.
Mineralization style is that of an two earlier porphyry copper events
telescoped by a highsulfidation epithermal Cu-Au deposit. The two porphyry Cu
phases are hosted, respectively younging age, to quartz diorite and hornblende-biotite diorite.
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SKARN
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Bessemer
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Larap, Jose Panganiban, Camarines Norte
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Ore mineralization is largely confined within the
skarn zone. Higher grade bodies are in the form of beds roughly parallel to
the skarn-shale (hornfels) contact at the footwall
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GOLD
- beauty and resistance to corrosion, most
ductile and malleable
- 75th in order of abundance among the elemen
- Green gold used in jewelry contains copper
and silver; white gold contains zinc and nickel, or platinum metals.
- Chlorauric acid is used in photography for
tonin silver images.
- Potassium gold cyanide is used in
electrogilding.
- The naturally occurring gold-silver alloy is
called electrum. Gold also occurs in telluride (tellurium-bearing)
minerals such as calaverite and sylvanite along with silver, and in the
mineral nagyagite along with lead, antimony, and sulfur. It occurs with mercury
as gold amalgam. It may be occasionally present in the sulfide minerals
pyrite, galena and sphalerite. Seawater also contains gold of up to 9
billion metric tons, but its recovery is yet to be economically feasible
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SILVER
- This white, lustrous metallic element
conducts heat and electricity better than any other metal.
- It is next to gold in terms of malleability
and ductility.
- It is harder than gold but softer than
copper.
- 66th among elements in terms of natural
abundance in the earth’s crust.
- Colloidal silver, dilute solutions of silver
nitrate (AgNO3), and some insoluble compounds, such as potassium, are
used in medicine as antiseptics and bactericides.
- Argyrol, a silver-protein compound, is a
local antiseptic for the eyes, ears, nose, and throat.
- cerargyrite (or horn silver), pyrargyrite,
sylvanite, and argentite.
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GEOLOGY AND OCCURENCES
- tensional splays oblique to the Philippine
fault zone
- Two major magmatic arcs, the Western Luzon
and Eastern Philippine arcs, are the most prolific gold producers in the
country.
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The gold
districts are
(1) Baguio-Mankayan gold district along the
western flank of Luzon Central Cordillera;
(2) Camarines Norte Gold District of southeastern
Luzon; and
(3) Masbate Gold district in northwestern Masbate Island.
(4) The
gold province is the Eastern Mindanao Gold
Province consisting of
three gold districts, namely, Surigao Gold District, Central Gold District,
and Masara Gold District.
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Philippine gold
deposits may be genetically divided into two groups:
1. primary-hypogene
gold-silver deposits
2.
secondary-supergene deposits
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NON
METALLICS
Industrial minerals and manufacturing materials including
cement raw materials, ceramics and refractory raw materials are dealt with in
this chapter. These minerals and
materials are as follows:
ASBESTOS
-Asbestos
though considered a significant industrial mineral utilized in fireproofing,
insulation, brake linings and asbestos cement early in 1980’s is now
considered non-commercial due to its carcinogenic property.
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CLASSIFICATION :
§ Shingles
§ Paper
§ plaster
LOCALITIES
Bangui
and Burgos, Ilocos Norte; Aguilar and Mangatarem, Pangasinan; Botolan,
Cabangan, San Felipe and San Marcelino, Zambales; Abra de Ilog, Mindoro
Occidental; Antique; Misamis Oriental and Bukidnon
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§ refuse grade
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§ Asbestos
§ Feldspar
§ Talc
§ Barite
§ Gypsum
§ Cement raw materials
§ Bentonite
§ Limestone
§ Ceramic raw material
§ Clay
§ Magnesite
§ Refractory raw materials
§ Diatomite
§ Perlite
§ Zeolite
§ Dolomite
Silica
BARITE
Barite is an
inert, heavy and stable mineral; hence, it is also called heavy spar.
Oftentimes, it is white, opaque and twinned, though impurities render the
mineral different colors like buff, gray and reddish. Barite is produced and
sold in several forms: jig concentrate, crude lumps, ground barite, or flotation
concentrate.
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LOCALITIES
Mabilog na
Bundok, Lobo, Batangas and in Mansalay, Oriental Mindoro
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BENTONITE
Bentonite is clay consisting predominantly
of minerals of the smectite group.
Bentonite is
an important mineral commodity used in foundry molding sands, drilling mud,
bentonite slurries for sealing porous strata and stoppage of water movement
in foundations for buildings, tunnels and dams, iron ore pelletizing,
bleaching oils and fats, carriers for insecticides and pesticides, and as
component of paints, pharmaceuticals, medicines and cosmetics.
Commercial
bentonite deposits are formed by alteration of fine-grained volcanic debris
deposited over relatively large areas. Other bentonite deposits are formed by
insitu hydrothermal alteration of coarse-grained intrusive rocks.
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CLASSIFICATION:
1.
SWELLING
TYPE
They
expand considerably, from 15 to 20 times of the original volume of dry
material in water and contain sodium as predominant exchangeable ion.
2.
Non
Swelling Tyoe
This
type has negligible swelling and carries calcium as its principal
exchangeable ion.
***Bentonites in the
Philippines are generally of the nonswelling type, the bulk of which is
classified as fuller’s earth.
LOCALITIES
Pangasinan,
Cagayan, Nueva Ecija, Batangas, Quezon , Albay, Cebu, Leyte, Davao del
Norte,
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GYPSUM
Gypsum is a
hydrous calcium sulphate (CaSO4.2H2O) containing 20 percent water. It is
obtained either from naturally occurring gypsum-bearing ores or from
fertilizer manufacturing, as by-products.
At present, the expanded production capacity of most cement plants in
the country requires large volume of gypsum as cement retarder. Likewise, the
manufacturing industry has greater need for gypsum in the fabrication of
fireproof gypsum board now proliferating among high-rise malls and
condominiums.
LOCALITIES:
Over the country, the known gypsum
deposits are disposed in four (4) provinces: Batangas, Albay, Camarines Sur
and Negros Oriental.
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LIMESTONE
Carbonate rocks are extremely common and make up approximately 15% of
the sedimentary column. They occur extensively in the Philippine archipelago
and vary in age from Cretaceous to Recent.
The cement
industry is the largest consumer of limestone.
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CLAY
Clay is an earthy substance consisting
chiefly of hydrous aluminum silicates with colloidal material and specks of
rock fragments, which generally become plastic when wet and stone-like when
fired.
The biggest reserves of
siliceous clay in the islands were formed by the residual alteration of
chloritic schists in Siruma, Camarines Sur.
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CLASSIFICATION:
1. RESIDUAL
These
deposits are widely distributed in the country. Many of these clay deposits
are formed from the chemical weathering of feldspar-rich rocks.
Cagayan, Ilocos Norte, Abra,
Benguet, Nueva Ecija, Pangasinan, Zambalez, Bulacan, Rizal, Laguna, Batangas,
Quezon, Camarines Norte, Camarines Sur, Sorsogon, Albay, Marinduque, Romblon,
Negros Occidental, Iloilo, Panay, Antique, Surigao del Sur, Misamis Oriental,
Bukidnon and Zamboanga del Sur and in Zamboanga City.
2. TRANSPORTED
Transported
clays are formed by accumulation in sites such as swamps and basins of clayey
materials transported by water
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DIATOMITE
Diatomite
or “diatomaceous earth“ consists mainly of siliceous shells or skeletons of
single-celled organisms called diatoms. It is composed essentially of
hydrated amorphous or opalline silica with varying amounts of contaminant
materials such as silica sand, clays, salts and organic matter.
LOCALITIES:
Diatomite deposits are in Pantabangan
and Caranglan, Nueva Ecija; Basud, Camarines Norte; Kapatagan, Lanao del
Norte; and in Quezon, Bukidnon.
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FELDSPAR
Feldspar is the general term for the group of rock-forming minerals
that are essentially anhydrous aluminum silicates. It is an important material in the
production of glass, fired clay products, and enamel paints.
Related to
intrusions
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MAGNESITE
Magnesite, a
natural form of magnesium carbonate with ideal magnesia content of 47.60
percent, is an important source of magnesium for industrial purposes. Magnesium is an essential element in plant
and animal metabolism, and is added to animal feeds in the form of
caustic-calcined magnesia.
LOCALITIES:
Lupon, Mati, Puntalinao, and Banay-banay,
Davao Oriental; small deposits are in Sibuyan Island, Romblon. .
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PERLITE
Perlite is a hydrated silicic volcanic glass, which generally has a
characteristic “onion-skin” or perlitic texture and a pearly luster. When expanded or bloated by shock
calcination, perlite forms an inert mass with an open texture having low bulk
density, low thermal conductivity, high sound absorption and fire-resistance.
LOCALITIES:
Perlite deposits are found in Calayan
Island, Cagayan; Baao, Camarines Sur; and in Maslog, Taysan, and Puro,
Legazpi City
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SILICA
Silica or
silicon dioxide (SiO2) commonly occurs as mineral quartz in varied forms; as
veins and lenses of bull quartz, as sand, pebbles, cobbles and boulders, and
as siliceous clays
About 85% of
silica sand are utilized in glass manufacture
CLASSIFICATION:
1.Silica in rock form ( Mindoro)
2.Silica in fragmental form (
Tagkawayan Quezon)
3. Siliceous clays ( Siruma Peninsula,
Camarines Sur)
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TALC
Talc is a layer-lattice mineral with the following composition,
Mg3Si4O10- (OH)2. It is the softest
common mineral with hardness of one (1) on Moh’s scale of hardness. Its cleavage flakes are flexible but not
elastic. It occurs in low to medium
metamorphosed basic or ultrabasic rocks and in place, constitutes the greater
part of the rock, producing the material known as steatite or soapstone.
LOCALITIES:
Abra, de Ilog, Mindoro Occidental;
Marangas, Brooke’s Point, Palawan and in Cabangan, Zambales.
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ALUMINUM
The main
source of aluminum is bauxite, a mixture of gibbsite (Al(OH)3), diaspore
(AlO(OH)), and boehmite (AlO(OH)).
Bauxite varies in colors from reddish-brown, white, tan, to
tan-yellow. It has dull to earthy
luster and can look like clay or soil.
Bauxite forms when silica in aluminum-bearing rocks (with high
feldspar content) is washed away (leached).
The major
producer of aluminum ore is Australia, which is said to produce over 40% of
the world’s reserves. Brazil, Papua
New Guinea, and Jamaica are also important producers. About 85% of all the bauxite mined
worldwide is used to produce alumina for refining into aluminum metal. Another 10% of the alumina produced is used
in the manufacture of chemical, abrasive, and refractory products. The
remaining 5% is used to make abrasives, refractory materials, and aluminum
compounds.
Bauxite in
the Philippines is commonly associated with karsted limestone and lateritic
terranes.
LOCALITIES:
These include
Batag Island, Hinabangan, Corcord, Guiuan, and Western Samar, Nonoc Island,
Bucas Grande
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MOLYBDENUM
Molybdenum
occurs chiefly as a secondary or accessory metal in porphyry copper and
copper skarn deposits in the Philippines, although it has also been
documented to occur elsewhere in quartz veins, pegmatites and bedded
sedimentary deposits.
Philippine porphyry copper deposits
and prospects range from gold-rich, molybdenumpoor deposits to relatively
molybdenum-rich, gold-poor end members. These molybdenum-rich deposits are
found in the provinces of Larap, Polillo Island, and Southern Negros while
the molybdenum-deficient deposits are in Baguio and Cebu. The molybdenum-rich, gold-deficient deposit
in southwestern Negros (Binulig, Sipalay, Aya-Aya) contains 0.01% Mo with 1
ppm Au. The central Cebu porphyry copper mineralization is characterized by
relatively high contents of both molybdenum and gold.
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MERCURY
The term “native mercury” is used for natural mercury found
associated with the mineral cinnabar.
Locality : Central Palawan
“Zambales Jade” Deposits, Zambales
It contains
sharply crystallized dodecahedral crystals of garnet, uvarovite, xenoblastic
feldspar, minor diopside and sphene that lie in a granoblastic mosaic of quartz
and plagioclase. This hornfelsic rock is composed of 67% feldspar (potash and
plagioclase), 18% quartz, 10% garnet; 4% sphene, and 3% diopside.
“Mindoro Jade”
Deposit, Occidental Mindoro
It is composed
of 40% muscovite, 50% sericite, 5% apatite and traces of quartz, calcite and
chlorite. The gemstone is petrologically
termed green mica schist due to the presence of abundant sericite.
Dasol Jasper
Deposit, Pangasinan
The deposit is in
San Vicente, Mabini and Barlo, Dasol.
Early prospectors used this jasper deposit as a guide in determining the
relative stratigraphic location of massive sulfide bodies. The inhabitants use
the jasper as sharpening stone or as aggregate for building materials. Later, this jasper was found to be of good
gem quality, thus paving the way for exploitation
Moss Opal
Deposit, Ilocos Norte
The moss opal deposit occurs as veins and
lenses within fractures, cavities and flow layers of andesite.
The moss opal is
milky white to brown, containing iron oxide in a moss or fernlike pattern.
