3.2 (2-5)

• Antonio Pigafetta, wrote that the people in the islands wore gold necklaces and other pieces of finely crafted jewelry.
• Smelting uses heat and chemical agents to chemically separate the desired metal from the other components of the ore.
• Leoncio Na Oy employs a small-scale mining method, which needs no heavy equipment.
• Gold is the most valuable metal in the Philippines.
• Silver is used in jewelry and other ornaments. It is always referred to as silvers or silverware.
• Copper is used mainly for electrical wires because of its high conductuivity.
• The most abundant metal is iron ore.
• Manganese is a silvery metal that often occur together with iron in earth's crust. It is mainly used in improving the quality of other metals.
• Nickel is also a corrosion-resistant metal that is used to enhance the quality of steel.
• Silica is the main raw material of glass.
• Asbestos had been widely used for insultation until its dust was found to cause cancer when inhaled.
• Gypsum is a soft mineral made up of calcium sulfate. It is used to make lightweight boards for ceilings and surgical splints and acts as coagulant for making soybean or tofu.
• Perlite is a volcanic material that serves as a substitute for diatomite in filters.
• Talc is the softest known mineral and has many uses in palstics.
• Tuff is composed of volcanic ash that has consolidated into a soft rock.
• Gems are precious or semiprecious stones formed from rock materials that were subjected to high temperature and pressure over a lon period of time.
• There are two distinct types of mineral that are classified as jade: nephrite and jadeite.
• Emerald, a green gemstone is a type of beryl, a mineral consisting of beryllium and aluminum silicate.
• Turquoise is an opaque blue-green gemstone. Historically, they were first mined in the Sinai peninsula and China.
• Panning involves putting soil into a shallow pan, which is deeper toward the center.
• Bentonite is a type of clay that is used for oil drilling and wine making
• Diatomite consists of the fossilized remains of diatoms