Sapphire and ruby are closely related, and are from a family of gemstones called corundum. Although sapphires are commonly thought of as blue, they can occur in a wide variety of colours, indeed pretty much every colour excluding red. Red sapphire is known as ruby.
Sapphire is an oxide, and is a hard gemstone, second only to diamond. Its hardness adds to its durability, which makes it perfectly suited to use in jewellery that is likely to be worn on a frequent or continuous basis, such as engagement rings. It is common to see inclusions (materials found within the gemstone) in natural sapphire, which are often related to its country of origin. Inclusion free natural sapphire would be very expensive.
Most gem-quality sapphire is heat treated to improve its colour. Evidence of heat treatments may be visible with careful inspection, but are not easy to detect. Sapphire may also be irradiated to change its colour, and surface fractures filled with glass to improve its appearance. Untreated sapphire of good quality commands a high price.
Synthetic sapphire is commonly seen, but can usually be identified as such with careful examination and / or testing by a gemmologist. Suspicions about sapphire being synthetic may be raised if a gemstone is clean inside (ie has no obvious inclusions), but falls within a relatively low price range.
Sapphire is the birthstone for September. At Wise Fig Jewellery we love using sapphire in our jewellery, have you seen our latest pieces?