Characteristics of minerals
Over 2,000 types of minerals discovered on earthy are in any of the 4 forms ;
1. Solid inorganic compound.
2. Liquid compound such as mercury, bromine and water.
3. Compound which is a product of the transformation of once living organism(s), such as petroleum.
4. Pure elements, i.e. gold, platinum and silver.
Primary ore deposits
1. Stream of mineral deposits in mountainous areas are formed by the cooling of igneous rock into vein. Magma or lava in narrow, enclosed space directly crystallizes into minerals. Chemical interaction of existing vein, i.e. change in temperature, may raise mineral contents. Examples are base metal (such as tin, tungsten and zinc) and non-metal (such as fluoride).
2. Mineral deposits in layers of rocks are formed by sedimentation or stratification, such as gypsum, rock salt, charcoal, oil and petroleum.
3. Mineral deposits composed of nodules are formed by decomposition of igneous rocks causing the embedded minerals to break into small chunks which are then washed away by water to foothills, river basins, or coastal plains. An area with accumulated minerals is called placer, such as tin placer, or a placer of antimony, precious stones, diamonds and gold.
Minerals being utilized can be grouped into tree types ;
1. Base metal is mineral that must undergo smelting. It is durable and opaque, has electrical and thermal conductivity and a melting point. Example are tin, steel, manganese, copper, lead, aluminum, magnesium, gold, silver and wolfram.
2. Non metal can be used without smelting, has no thermal conductivity, and is translucent or brittle, Example are fluoride, phosphate, rock, sand, salt, sulfur, potassium, calcium and kaolin.
3. Energy or fuel mineral is mostly formed from fossils, such as charcoal, crude oil and natural gas.
1. Dredging is the mining method used for fertile placers. Minerals are dug and washed on dredging boats.
2. Gravel pump mining is operated in placers which are not so fertile. The areas are drilled or blasted by human labor or high-pressure water. The mixture of minerals, sands and rocks are pumped up for separation.
3. Ground sluicing is operated along foothills or slops using human labor, high pressure water and excavators to disintegrate the soil and then the materials are transported through a sluice.
4. Open-pit mining is operated on foot-hills or hilly areas. The areas are shaped into terraces and human labor or machines are used to transport rocks and minerals for separation on lower ground.
5. Hydraulic mining is operated in placers near main waterways on highland. A dyke is built to block a waterway and away soil and rack mixed with minerals and carry them downstream for separation.
6. Underground mining is done when minerals are too far underground. Minerals are mostly low in volume but scare, such as gold. The areas are blasted and drilled to create intersecting “rooms”. Beams are installed to hold up thr roof for safety.