Blue sapphire

This natural sapphire has a deep blue colour, a size of 3.40 mm and a weight of 0.20 carats, and is graded as having no visible inclusions, with no flaws to affect its appearance or value. Sapphire has been heat-treated to improve its colour and clarity, a common and accepted process in the jewellery industry. Sapphire comes from Sri Lanka, a country renowned for the quality and diversity of its sapphires.

All corundum gemstones are known as sapphire with the only exception being the ruby red variant which is called ruby. However, the name sapphire is very common for blue gemstones, but this blue should not be understood as the colour of clear sky, but all shades of blue up to very dark blue and even black. Sapphire is found in a wide range of colours and shades. Sapphire is a mineral that occurs as Al2O3 single crystals. The colour is determined by impurities such as Fe2+, Fe3+, Cr3+, Ti4+ or V4+. It has a hardness of 9 on the Mohs scale, after diamond.