Gemology and Gemstone Instruction Gemology is the study of gemstones, which includes gem properties, locations and origins. Gemology is often studied by people in the jewelry business, including business owners, buyers, designers and appraisers. Others studying gemology include antique dealers and auction house catalogers. A gemstone is a mineral, rock or organic material that is used for jewelry, ornamentation, or art. A gem, such as a diamond, is a type of gemstone that must be cut and polished for its beauty to be visible. A gemstone can be valued for its natural growth having the traditionally quoted “three cardinal virtues” of beauty, durability and rarity. Acceptability and portability are other factors decided by the society for valuation of gemstones. Beauty is related to the results of the visible light by interaction with the gemstone. These effects are different for different types of gem materials, especially in relation to the degree of transparency. Durability is related to the structure, which depends on hardness against scratching, toughness against breaking and stability against external forces such as heat, pressure, shock and chemical action etc. Rarity of a gemstone depends on its availability, and the valuation is decided by the supply and demand theory in economics. 1. It's not necessary for auction house catalogers to study the gemology.