Philippine Mineral Resources Information Series

Vocabulary flashcards covering the characteristics, mineralogy, history, and occurrences of various metallic and non-metallic mineral resources in the Philippines, based on the Mineral Resource Information Series.

Iron (Fe)

A lustrous, ductile, malleable, silver-gray metal that is the fourth most common element in the earth’s crust and second most abundant metallic element, constituting about $5\%$ by weight.

Hematite

A principal iron mineral known as ferric oxide ($Fe_2O_3$), characterized by a reddish-brown to black color and dull earthy or metallic specularite varieties.

Magnetite

A ferrous-ferric oxide ($Fe_3O_4$) characterized by strong magnetism; it may act as a natural magnet known as lodestone.

Skarn

The most important iron deposit type in the Philippines, occurring where limestone or calcareous sediments are intruded by a younger intermediate to acidic pluton.

Batas Pambansa Blg. 265

An act approved on Nov. 13, 1982, prohibiting the extraction of gravel and sand from beaches in the Philippines.

Nickel (Ni)

A silvery-white, magnetic metallic element isolated in 1751 by Baron Axel Frederic Cronstedt, ranking about 22nd in natural abundance in crustal rock.

Garnierite

A high-grade hydrous nickel silicate belonging to the serpentine group of minerals that often appears as green coatings along fractures in the saprolite zone.

Chromite

The only important ore of chromium ($FeCr_2O_4$), classified as metallurgical, refractory, or chemical depending on the chrome to iron ratio.

Podiform deposits

Primary chromite bodies formed by igneous processes, also known as Alpine-type deposits, typically found within the ultramafic portions of ophiolite complexes.

Manganese (Mn)

A silver-gray, brittle metallic element ranking about 12th in abundance in the earth's crust, first isolated in 1774 by Johan Gottlieb Gahn.

Pyrolusite

The principal ore of manganese, composed of manganese oxide ($MnO_2$).

Copper (Cu)

A ductile and malleable metal with high conductivity, found in the Philippines primarily in porphyry copper, volcanogenic massive sulfide (VMS), and epithermal vein deposits.

Porphyry copper deposits

Hypogene sulfide deposits where ore minerals are disseminated in grain impregnations or networks of veinlets within acid to intermediate bodies and their host rocks.

Kuroko-type

Strata-bound polymetallic massive sulfide deposits genetically related to submarine acid volcanic activity, typically containing Cu, Pb, Ag, and Au.

Electrum

A naturally occurring alloy consisting of gold and silver.

Troy ounce

The standard unit used in weighing gold, equivalent to $31.1\,g$.

Guano

Accumulated excrement and remains of birds and bats found in limestone caves, serving as an organic source of phosphorus and nitrogen.

Barite

Also known as heavy spar, it is an inert, heavy mineral ($BaSO_4$) used as a weighting agent in oil well drilling and as an industrial filler.

Bentonite

Clay consisting predominantly of minerals of the smectite group, classified locally as swelling (sodium) or non-swelling (calcium) types.

Diatomite

Also called diatomaceous earth, it consists mainly of siliceous shells or skeletons of single-celled organisms called diatoms, composed of hydrated amorphous or opalline silica.

Feldspar

A group of rock-forming anhydrous aluminum silicate minerals used as a flux in ceramics to promote fusion and impart strength.

Gypsum

A hydrous calcium sulphate ($CaSO_4 \cdot 2H_2O$) containing $20\%$ water, utilized as a retarder in Portland cement manufacture.

Marble

Commercially, any crystalline rock predominantly composed of calcite, dolomite, or serpentine that takes a good polish; geologically, a metamorphic limestone or dolostone.

Adobe

The local name for volcanic tuff (specifically the Diliman Tuff) used as a dimension stone for construction and decorative architecture.

Tektite

Small, rounded, pitted bodies of silicate glass known locally as ‘bisnu,’ found in riverbeds and alluvial plains like those in Paracale, Camarines Norte.

Bauxite

The main source of aluminum, consisting of a mixture of gibbsite ($Al(OH)_3$), diaspore ($AlO(OH)$), and boehmite ($AlO(OH)$).

Cinnabar

The chief mercury mineral ($HgS$), typically found in porous or fractured rocks that allow passage for ore solutions or vapors.

Galena

The chief ore of lead, chemically known as lead sulfide ($PbS$).

Sphalerite

The chief ore of zinc, chemically known as zinc sulfide ($ZnS$).

Zeolite

A group of minerals formed from the diagenesis of volcanic glass in sedimentary rocks; includes clinoptilolite and mordenite zones.