Diamond

The hardest naturally occurring substance known to man, diamonds are a crystalline form of pure carbon. Prior to modern day discoveries in Brazil and South Africa, the only known source of diamonds was India. In ancient times diamonds were called adamant, meaning "indestructable". Most diamonds are irregular in shape and rather unappealing to the eye. The color ranges from dull yellow to dirty brown.

Jewel grade diamonds—colorless stones having a perfect crystalline shape—are extremely rare, and the technology for cutting and polishing them did not exist until the early Renaissance. As a result, diamond jewelry was more or less non-existant in Europe during the Middle Ages. Polishing with diamond dust and grindstones began in Burgundy c.1400. In 1465 the first diamond cutter was recorded in Belgium, and by 1610 the diamond cutting trade was well established in Antwerp. Early diamond cutting was fairly simple. The Mazarin cut did not appear until 1650. The Peruzzi cut, invented c.1700, eventually developed into the brilliant cut of modern times.

See also:

• Diamond according to Maplet's A Greene Forest

References:

• Sydney H. Ball, A Roman Book on Precious Stones (includes Eng. trans. of C. Plinii Secundi liber xxxvii de Naturalis Historia), Los Angeles, 1950
• Cariadoc's "On gemstones"
• Eduard Gübelin & Franz-Xaver Erni, GEMSTONES: Symbols of Beauty & Power, Tuscon AZ, 2000
• Walter Schumann, Gemstones of the World, New York, (rev) 1997

The following photos may prove useful (you may need to scroll down to view):

• [1]uncut diamond (from Gemnation.com)
• [2]diamond in the rough (Diamond Helpers.com)
• [3]historical diamond cuts (Wikipedia.org)