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Birthstone for  July

This is a natural rough parcel heat treated /glass filled showing stunning colours of red with a purplish tinge.This specimen can be cut into a large specimen or it is ideal as a carving piece.

Mohs scale 9

Weight   ct

Size  x  x  mm app

A Ruby is a pink to blood-red gemstone  a variety of the mineral corundum (aluminium oxide]. The common red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires. Prices of rubies are primarily determined by color. The brightest and best "red" called pigeon blood-red, commands a huge premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone will command a premium, but a ruby without any needle-like rutile inclusions will indicate that the stone has been treated one way or another. Cut and carat (size) also determine the price

TREATMENTS

The most common treatment is the application of heat. Most if not all rubies at the lower end of the market are heat treated on the rough stones to improve color, remove purple tinge, blue patches and silk. These heat treatments typically occur around temperatures of 1800°C (3300°F).Some rubies undergo a process of low tube heat, when the stone is heated over charcoal of a temperature of about 1300°C (2400°F) for 20 to 30 minutes. The silk is only partially broken as the color is improved.

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