Sapphire is a gemstone variety of the oxide mineral corundum, comprising of the two elements aluminium and oxygen. These are the chemical “ingredients” required to form sapphire crystals. Sapphire is the name given to all gem-quality corundum that is not red (which is called ruby) or pinkish-orange (which is called padparadscha).
Although sapphire is generally thought of as a blue gemstone, pure corundum (aluminium oxide) is colourless. In fact, blue sapphire occurs when the crystals contain small amounts of iron and/or titanium. Iron will also give corundum a yellow or green colour. In a similar way, trace elements of chromium can turn corundum pink, and hence forming pink sapphire.
Blue Sapphire, 2.55 Carat, Oval Cut
Sapphire can also demonstrate different shades of blue/purple in natural or artificial light. These beautiful stones are called “colour-change” sapphire.
On the Mohs scale of hardness, sapphire is rated as a 9 (as is ruby), making it second only to diamond in terms of its resistance to scratching. This is one of the reasons why it is a popular choice in jewellery that is worn regularly, such as engagement rings.
Pink Sapphire, 1.00 Carat, Oval Cut from Sri Lanka
The vast majority of blue sapphires on the market today have been heat treated in some way to improve their colour and clarity. Heat treatment in a gas or electric furnace is now a standard procedure in the gem industry. Sapphires and rubies may also be subjected to other treatments, such as radiation, diffusion and glass filling.
Some of the best blue sapphire in the world has historically originated in Ceylon (Sri Lanka) and Kashmir. The term “Kashmir Sapphire” is sometimes applied to outstanding examples of this gemstone, even when the stone itself did not come from that region.
Ceylon / Sri Lanka has been an important source of sapphires and rubies for more than 2000 years. The stones are still mined by hand from gravel deposits that cover most of the southern half of the island. Sapphire from Sri Lanka can be a wide range of beautiful blues, but are typically light-to-medium blue. Some of the largest Sri Lankan cut gemstones weigh up to several hundred carats.
Blue Sapphire, 2.62 Carats, Rough Crystal
Sapphire can also be found in a number of other locations around the world including Madagascar, USA, Myanmar, Australia and Thailand.
Yellow Sapphire, 1.02 Carat, Oval Cut
Throughout history, sapphire has been a symbol of truth, sincerity and faithfulness in relationships. It is said to bring peace, joy and wisdom to the wearer and owner. In the past, the sapphire was also believed to be a talisman that would give protection against evil spirits. Sapphires are also said to represent “divine favour” they have traditionally been a favourite gemstone for kings and queens. For example, the British Crown jewels contain many blue sapphires.
View our range of sapphire gemstones, all ethically sourced and fully traceable, in our gemstone store.
Green Sapphire, 0.89 Carat, Oval Cut
Orange / Pink Sapphire, 0.73 Carat, Pear Cut