Sapphires are the most liked gemstones, and one of the most interesting ones is Black Star Sapphires. The name star has come because of its appearance. When this stone is seen under a flashlight, it shows a bedazzling star image on the stone that gives out a beam of 6 rays altogether, forming a star. Wearing Black Star Sapphire gemstone is considrered to be auspicious and is most liked by men. Among all Black Star Sapphire, the most precious one is Thai star sapphire.
Though this gemstone is black under the flashlight, it will have a golden star effect on the surface. This gemstone has a level of hardness 9 on the Mohs scale, which is similar to or near to diamond; thus, it is the hardest substance next to diamond and is very durable to wear in rings and jewellery for long-term use.
The Black Star Sapphire are heated at a very high temperature of about 1600-1800 degrees Celsius, thus enabling them to become shiny and colourful and enhancing their properties. They are treated with titanium to improve the effectiveness of the star on its surface. They may have high hardness, but they should only be cleaned properly with a soft cloth and soapy water.