Characteristics and Properties of Natural Diamond

Gemstones are identified by the foiiowing characteristics (known as the four C s). 

Unprocessed natural diamond has a surface that can be brilliant (adamantine), frosted or dull. It comes in many colors from black to essentially colorless. These colors are caused by impurities or by defects in the crystal lattice and, among gemstones, the most common are pale yellow, pale green, pale blue, and pink. Pale blue is the most valuable and is the color of the finest gemstones such as the famous Hope diamond.1 1 

Natural diamond is divided in four types based on optical and other physical characteristics and usually derived from the amount and distribution of nitrogen within the crystal lattice. These types are described in Ch. 11. Sec. 3.1 and 3.2, and Table 11.2. 

The physical and chemical properties of natural diamond are generally similar to the properties of the single crystal reviewed in Ch. 11. 

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