Gemology is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.
Special Gemology deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.
Diamond clarity is the quality of diamonds that relates to the existence and visual appearance of internal characteristics of a diamond called inclusions, and surface defects, called blemishes. Clarity is one of the four Cs of diamond grading, the others being carat, color, and cut.
Inclusions are solids, liquids, or gases that were trapped in a mineral as it formed. They may be crystals of a foreign material or even another diamond crystal, or may have produced structural imperfections, such as tiny cracks that make a diamond appear whitish or cloudy. The number, size, color, relative location, orientation, and visibility of inclusions can all affect the relative clarity of a diamond. A clarity grade is assigned based on the overall appearance of the stone under ten times magnification, which is a magnification standard for loupes used in the gem world.