A 2.45 Carat Antique Cushion Cut Diamond. Photo Courtesy of Lang Antiques

Diamond is a gemstone with a cubic crystal structure composed of chemically pure carbon and manifesting extreme hardness resulting from the incredibly strong chemical bonds between the carbon atoms. Diamonds are valued for their brilliance, fire and beauty. Most people think of diamonds as being colorless, but they occur in every color including: yellow, green, pink, blue, purple and red. Diamond color and clarity can be altered such treatments as irradiation, heat and high pressure.

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Victorian Diamond Chandelier Earring. Photo Courtesy of Lang Antiques

For over 2,500 years the only known source for diamonds was the Golconda region in India. After the depletion of the diamond mines in India c. 1700s, a new diamond deposit was discovered in Brazil c.1725. Brazil quickly became largest supplier of diamonds worldwide and remained so until the discovery of diamonds in South Africa in 1866. De Beer's Consolidated Mines LTD was formed in 1888 to stabilize the South African diamond market and maintained a near monopoly on the diamond trade for over 100 years, controlling 80% of the market. Today their market share is less than 50%.

The value of a diamond is set by applying what is known in the diamond business as the four C's which include measurement of a diamond's color, clarity, carat weight and cut. Diamond color is measured on a scale ranging from D to Z with D being the most colorless (and most desirable). Clarity has a series of designations that range from Flawless to Included which represent the relative number, type and visibility of inclusions. Carat is a measure of weight where one carat is equivalent to 1/5 of a gram or 200 milligrams. Cut includes the shape of the finished diamond as well as a determination of how well the diamond was fashioned, its proportions and finishing details.

Diamond is the birthstone for the month April and commemorates the 10th and 60th - 65th in some countries - anniversary.

Gemological information for diamond
Color All colors
Crystal Structure Cubic
Refractive Index 2.417
Durability Excellent
Hardness 10
Similar stones Diamonds can be confused with a large variety of colorless gemstones and synthetic gemstones:Zircon, Cubic Zirconia, Moissanite, YAG, Strontium Titanate, Leaded Glass, Rhinestone and Synthetic Rutile
Treatments Heat Treatment, Irradiation, Fracture Filling
Country of origin Diamond deposits are found all around the world. The most notable being Africa, Australia, India and more recently Canada
Diamond care
Ultrasonic cleaning Safe unless the stone is fractured
Steam cleaning Safe unless the stone is fractured
Warm soapy water Safe
Chemical attact No reaction
Light sensitivity None
Heat sensitivity Diamond is an excellent conductor

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