FUN FACT ABOUT YOUR SEPTEMBER BIRTHSTONE: Sapphire- is a gem - TopicsExpress



          

FUN FACT ABOUT YOUR SEPTEMBER BIRTHSTONE: Sapphire- is a gem quality variety of the mineral corundum. It is the second hardest substance on earth after diamond, rating 9 on the Mohs scale of mineral hardness. Corundum itself is not a very rare mineral, but gem quality corundum is extremely rare. Most corundum is opaque to translucent and heavily included, suitable only for industrial use, including the production of abrasives used for sandpaper and machining of metal, plastics and wood. The name corundum comes from the Sanskrit word kuruvindam, meaning ruby sapphire, while the name sapphire comes from the Persian word safir, derived from the Greek word for blue. In times of antiquity and the Middle Ages, the term sapphire actually referred to lapis lazuli, but in the early 19th century, the description and definition of sapphire was changed to the corundum variety we know today. Coloured sapphire (other than blue) is often referred to as fancy sapphire, and fancy sapphire is typically traded using color-specific names, such as yellow sapphire, green sapphire or purple sapphire. In the past, there were several misleading names used for fancy sapphire varieties, most of which are no longer used, such as Oriental peridot, a term which was used to refer to green sapphire. Sapphire is found in only a few locations in the world. The three most famous regions for blue sapphire are Kashmir, Burma and Sri Lanka. Sapphire has also been mined in Cambodia, Thailand, Vietnam and India. As of 2007, Madagascar has been leading the world in sapphire production, though Sri Lanka continues to be the only steady producer of fine quality blue sapphire. Sri Lanka and Madagascar produce sapphires in a wide range of colors and whilst Sri Lanka has been a known sapphire source for centuries, sapphire deposits in Madagascar were only recently discovered in 1998. The enormous deposits found in the village of Ilakaka came as a big surprise and led to a gemstone fever reminiscent of the 19th century Californian gold rush. Today, Madagascar and Tanzania are considered to be two of the most important sapphire sources. Australia is also known for significant sapphire deposits, though most Australian sapphire is known to form rather dark in color. In the USA, there are small sapphire deposits found throughout Montana and North Carolina.
Posted on: Tue, 09 Sep 2014 23:35:29 +0000

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