|
diamond: Definition and Much More from Answers.com (10637 words) |
 | Diamonds are found in alluvial (loose earthy material deposited by running water) formations and in volcanic pipes, filled for most of their length with blue ground or kimberlite, an igneous rock consisting largely of serpentine. |
 | Diamonds have also rarely been found in deposits left behind by glaciers (notably in Wisconsin and Indiana); however, in contrast to alluvial deposits, glacial deposits are not known to be of significant concentration and are therefore not viable commercial sources of diamond. |
 | Diamonds which are not cut to the specifications of Tolkowsky's round brilliant shape (or subsequent variations) are known as "fancy cuts." Popular fancy cuts include the baguette (from the French, meaning rod or loaf of bread), marquise, princess (square outline), heart, briolette (a form of the rose cut), and pear cuts. |