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	Cape			Cape is a term commonly used to refer to diamonds with a distinct yellow body color named after early diamonds from Cape Province, South Africa. These faint to light yellow diamonds range from the L - Z color range on the GIA color-grading scale.
	Carat or Carat Weight			One of the 4C's, carat refers to the measure of weight of a diamond. One carat is equivalent to 200 milligrams or 0.2 gram. One carat can also be divided into 100 "points". A .25-carat diamond is the same as a 25-point or 1/4-carat diamond.
	Cavity (Cv)			Space left when a surface-reaching crystal drops out of or is forced out during polishing.

	Certificate			Many diamonds are certified by an independent laboratory where they are evaluated by an independent gemological laboratory with skilled gemologists who use specialized equipment to measure and evaluate each diamond’s particular characteristics and attributes. This information is provided in written form and is called a diamond grading report or diamond quality document. Although there are several reputable independent grading laboratories, the best known laboratories are the Gemological Institute of America's (GIA) Gem Trade Laboratory, the European Gemological Laboratories (EGL), the Hoge Raad vor Diamont (HRD), the American Gem Society (AGS) and the International Gemological Institute (IGI).

	Channel Setting			In the channel setting, ridges in the metal create a channel that holds diamonds securely in place with no metal between the stones. This type of setting protects the girdle area of the diamond, as well as securing small stones more effectively than a prong setting. Channel-set diamonds also sit flush with the mounting, making them less likely to get snagged on other objects.
	Chip (Ch)			A shallow opening caused by damage to the stone’s surface.

	Clarity			Clarity is one of the 4C's and is defined as a gemstone's relative freedom from inclusions and blemishes. Inclusions are a type of clarity characteristic enclosed within a gemstone that might extend into the diamond from the surface. Blemishes are confined to the gemstone's surface. Together, inclusions and blemishes help establish a gem's unique identity and quality. Most inclusions are undetectable by the naked eye and can only be seen with 10x magnification. The GIA and EGL have a detailed system of rules to summarize the size, number, position, location and type of clarity characteristics in a diamond. There are eleven clarity grades: • Flawless • IF (Internally Flawless) • VVS1/VVS2 (Two categories of Very, Very Slightly Included) • VSI/VS2 (Two categories of Very Slightly Included) • SI1/SI2 (Two categories of Slightly Included) • I1/I2/I3 (Three categories of Included) Blemishes usually only affect the clarity grades in the top two categories, Flawless and Internally Flawless. Inclusions affect all clarity grades.

	Cleavage			Cleavage is a small crack along a plane inside a diamond. A cleavage usually does not affect the integrity of a diamond and may be hard to find under 10x magnifications.

	Cloud (Cld)			Several tightly grouped pinpoints that might be too small to distinguish individually at 10x magnification but together have a hazy, cloud-like appearance.

	Color			Color is one of the 4C's that helps determine the quality and value of a diamond. Colorless diamonds are graded on a color scale established by the Gemological Institute of America (GIA). The normal color range scale starts at D (colorless) through Z (light yellow or brown). The letters in the D-to-Z scale do not describe the actual color but describe the depth of color in a diamond. Each letter represents a range of color based on a combination of hue (color), tone (lightness or darkness), and saturation (intensity). There are five color ranges in the normal color range: • Colorless: D, E, F • Near-Colorless: G, H, I, J • Faint: K, L, M • Very Light: N, O, P, Q, R, S, T, U • Light: V, W, X, Y, Z Fancy colored diamonds refer to diamonds outside the normal color range scale (past the Z color range) with hues like pink, blue, green, yellow, orange and very rarely red. Fancy colors are not included in this color scale and are considered extremely rare. Absolutely colorless stones in the D color range are also considered extremely rare and valuable.

	Colorless			This term describes a transparent diamond or gemstone completely devoid of body color. Colorless diamonds include diamonds in the D, E, and F color range on the GIA color grading scale.
	Comfort-Fit			A comfort-fit band has a rounded inside edge of a wedding band which results in comfortable wear.

	Conchiolin			The organic “glue” in nacre that holes calcium carbonate platelets together. It is similar in composition to material found in human hair and fingernails.

	Crown			The part of a diamond above the girdle plane.

	Crown Angle			Crown angle is the angle measured between the girdle plane and the bezel facets. Along with table size, crown angle determines the amount of dispersion a finished diamond displays.


	Crystal (Xtl)			A mineral crystal contained in a diamond

	Culet			The bottom point of the diamond. It may be polished in some stones. Please note that sometimes the cutter may choose to make the culet a surface instead of a point.

	Cultured Pearl			A cultured pearl is created through mimicking the natural pearl process in a controlled environment.

	Cushion Cut			A mixed cut diamond shape that looks like a square pillow.

	Cut			One of the 4C's, cut refers to the proportions and finish of a diamond and is sometimes referred to as the make of a diamond. A well-cut diamond will internally reflect light from one mirror-like facet to another and disperse and reflect it through the top of the stone. This results in a display of brilliance and fire. Diamonds that are cut too deep or too shallow leak light through the side or bottom, resulting in less brilliance and ultimately value.