Tag Archives: corundum

The science of sapphire – a gemmological view of September’s birthstone

Many people are impressed with the sheer beauty and sparkling magnificence of sapphire, but behind the dazzling outward appearance, there are plenty of fascinating facts and figures. Some of these attributes are essential for gemmologists for identification purposes. Sapphire is a gemstone variety of the oxide mineral corundum, comprising of the two elements aluminium and […]

Star sapphire, 22.41 carat, cabochon cut

Sapphire – the star attraction

One of the most fascinating and rare varieties of sapphire is the so-called “star” sapphire. This member of the corundum family exhibits a clear star shape (or asterism) under certain lighting conditions. When viewed using a strong source of direct light (such as a torch or penlight), a six-ray star will appear on the surface […]

Blue sapphire - side view

Sapphires are blue and rubies are red… right?

There is a common misconception that all sapphires are blue and all rubies are red. However, there’s a lot more to the colour of these stones than one might think. Both of these precious gemstones belong to the same family of stones, called corundum. Scientifically speaking, all corundum (both sapphire and ruby) is created equally […]