Mineralogy:

Mineralogy:

Mineralogy is a part of geology. It is the study of various properties, origin, classification, composition of minerals and their usages. Mineralogist identifies the minerals as well. Identification of minerals is made according to their chemical, physical and crystallographic characteristics. Minerals are the source of valuable metals, most frequently mined in the form of ore.

Chemical composition of minerals is the most important property for identifying and distinguishing them. They generally form

(i) as elements, such as for gold, diamond, graphite, sulfur;

(ii) sulphides, such as galena and sphalerite, ore of lead, copper, or silver;

(iii) oxides, such as haematite (Fe2O3), bauxite (Al2O3· H2O);

(iv) halides, such as halite (NaCl) ;

(v) carbonates, calcite (CaCO3);

(vi) phosphate, such as apatite;

(vii) sulphate, such as barite (BaSO4);

(viii) silicate, such as quartz, feldspar, mica, silica (SiO4).

Some of the minerals are very colorful. In ancient time colors are made by grinding colorful minerals. Many colorful minerals are used as gems stones. Gemstones are treasured for their beauty and durability. Their value depends on beauty, hardness, its rarity and types of cutting & polishing made on the stone. Diamond, rubies, emerald, sapphire etc., attract greatest value.