Diamonds were used to engrave gemstones in India by 300 BCE.
Diamonds can be burned. To burn a diamond, it must be heated to between 1290-1650 degrees Fahrenheit. House fires and jewelers’ torches can sometimes reach that temperature.
D-to-Z color diamonds are the most widely used in jewelry, but diamonds come in all colors of the rainbow. For natural colored diamonds, blue, green, orange and red are the rarest; yellow and brown are the most common.
Diamond weight is measured in carats (not carrots or karats). The word carat is derived from keration, the Greek name for the carob tree whose seed was used for centuries as the standard of weighing precious stones. Because the seed could vary slightly in weight, in 1913, carat weight became metric; one metric carat is equivalent to 0.2 grams or 0.007 ounces.
The largest rough diamond, discovered in 1905, is the Cullinan diamond, weighing in at 3,106 carats (ct.)!