Diamond
Diamonds are considered precious stones and are comprised of crystallized carbon. They are the hardest stone, and can only be cut using another diamond or a wheel that has been treated with diamond powder or dust. Colors of diamonds range from colorless to yellow, brown, and rarely green, blue, reddish, or orange black. Diamonds are found in many parts of the world, including South Africa, Russia and Australia. Diamonds are graded by the Four C's: Carot (size), Clarity (lack of inclusions), Color and Cut.
Diamond is the April birthstone and represents tenth, twentieth and sixtieth (Diamond Jubilee) anniversaries. Diamonds are commonly used for Western engagement and wedding rings (men's and women's) in many different cuts and settings.
Because of the expense of diamonds, they are not commonly drilled and used in beaded jewelry. Swarovski crystals or glass beads can be used to achieve a diamond "look" in a beaded piece.