In the symbolism of gemstones, the diamond represents steadfast love. Diamond is a mineral composed of pure carbon. It is the hardest naturally occurring substance known and the most popular gemstone. The hardness, brilliance, and sparkle of diamonds make them unsurpassed as gemstones. Diamonds vary from colourless to black, and they may be transparent, translucent, or opaque.
Most diamonds used as gems are transparent and colourless or nearly so.
Orange, violet, yellow and yellowish green more common colours. May Birthstone - Emerald Emerald comes indirectly from the Greek, smaragdos , a name that seems to have been given to a number of stones having little in common except a green color. Greek miners were working the mines in the time of Alexander the Great and later the mines yielded their gems to Cleopatra. Significant deposits are in Columbia. There are deposits in Brazil but the stones are lighter than Columbian ones, mostly yellow green.