Gemology (gemmology outside the United States) is the science, art and profession of identifying and evaluating gemstones. It may be considered a branch of mineralogy. Some jewelers are gemologists and are qualified to identify gems. The scope of this article is limited to the empirical sciences. ... Venus de Milo exhibited in the Louvre museum, France. ... A selection of gemstone pebbles made by tumbling rough rock with abrasive grit, in a rotating drum. ... Mineralogy is an earth science that involves the chemistry, crystal structure, and physical (including optical) properties of minerals. ... Jewellery (Jewelry in American spelling) comprises ornamental objects worn by persons, typically made with gemstones and precious metals. ...

With further training they can become appraisers (valuers). There are professional schools and associations of gemologists and certification programs.

Some gemologists specialize in various gemstones, such as diamonds or emeralds. Such specialists are found in fields in which a great deal of knowledge is required, especially in the determination of exceptionally "pure" gems. For other uses, including the shape â—Š, see Diamond (disambiguation). ... Emerald (Be3Al2(SiO3)6) is a variety of the mineral beryl, colored green by trace amounts of chromium and sometimes iron. ...

Recently, the demand for gemological services has grown, as increasing quantities of synthetic gems such as cubic zirconia and synthetic moissanite are manufactured. Gemologists perform such work as the identification of synthetic and natural gemstones, fracture-filled gemstones, and color-enhanced or treated natural gemstones. Gemology in the 21st century has become a rigorous science where constant study is necessary for correct identifications. A round brilliant-cut cubic zirconia Cubic zirconia (or CZ) is zirconium oxide (ZrO2), a mineral that is extremely rare in nature but is widely synthesized for use as a diamond simulant. ... Moissanite is a trade name given to silicon carbide (chemical formula SiC) for use in the gem business. ...

Gemstones are basically catogarized on basis of its atomic structure ,its specific gravity and on base of its optical properties.

Gemmologists studies these factors while valuing or appraising cut and polished gemstones. By way of its atomic structure gemstones are scientifically catogrized . The otpical properties catogarize single refractive or Double refractive and further the gemstones is studied under a gemmological microscope to study its internal structure which reveals whether it is synthetic or is natural.( reveals air bubbles and cavities caused by natural and treatments during enhancement of colour)

The spectrum analysis of cut gemstones also allows a gemmologist to understand the chemical structure and identify its origin as it is a major factor in valuing a gemstone.

For example a ruby from Burma will have definite internal and optical activity variance as compared to a thai ruby.

But these are ways of identifying only the cut and polished but when the gemstones are in a rough state , the gemmologist study the outer structure, its companion rock and also by polisihing off a side its colour. Mostly the stone is identified by its colour , specific gravity and its place of origin.

(Sanjeev Rao - Gemmologist , CBD Belapur ,India)