Today In - 'Useless Info'

A diamond is the hardest natural substance on earth, but if it is placed in an oven and the temperature is raised to about 1405 degrees Fahrenheit, it will simply vanish, without even ash remaining. Only a little carbon dioxide will have been released.


Diamonds are formed over a period of a billion or more years deep within earth's crust - about 90 miles deep and is pushed to the surface by volcanoes. Most diamonds are found in volcanic rock, called Kimberlite, or in the sea after having been carried away by rivers when they were pushed to the surface.


A diamond is 58 times harder than the next hardest mineral on earth, corundum, from which rubies and sapphires are formed. It was only during the 15th century that it was discovered that the only way to cut diamonds was with other diamonds. Yet, diamonds are brittle. If you hit one hard with a hammer, it will shatter.


The world's largest diamond was the Cullinan, found in South Africa in 1905. It weighed 3,106.75 carats uncut. It was cut into the Great Star of Africa, weighing 530.2 carats, the Lesser Star of Africa, which weighs 317.40 carats, and 104 other diamonds of nearly flawless color and clarity. They now form part of the British crown jewels.


Not all diamonds are white. Impurities lend diamonds a shade of blue, red, orange, yellow, green and even black. A green diamond is the rarest. It is not the rarest gemstone, however. That title goes to a pure red ruby. Diamonds actually are found in fair abundance; thousands are mined every year. 80% of them are not suitable for jewelry - they are used in industry. Only diamonds of higher clarity are sourced to the jewelry stores.


A diamond carat differs from a gold carat. The gold carat indicates purity - pure gold being 24 carats. One diamond carat is 0.007055 oz. The word carat derives from the carob bean. Gem dealers used to balance their scales with carob beans because these beans all have same weight.