Sapphire Properties, Facts and Photos
What is Sapphire?
Sapphire is a variety of the mineral corundum. Corundum, which is colourless in its purest form, is a crystalline form of aluminium oxide, meaning it's a chemical compound of aluminium and oxygen.
Trace impurities such as iron, titanium, and chromium produce a variety of colours. Iron and titanium give sapphire its blue colour. Other colours depend on the impurities present.
Chromium causes hues of pink to red, iron causes yellow to green, and vanadium can produce shades of purple. White sapphire, which is quite rare, is free from impurities.
The colour change occurs when these impurities replace atoms in the base mineral, corundum.
Sapphire has an almost identical chemical composition to ruby, which is red corundum. Red corundum is always known as ruby, all other colours are sapphire.
Although sapphire can be found in many colours, pink and blue are the most popular. Sapphire is more common than ruby.
The name 'sapphire' comes from the Greek word 'sappheiros', which is believed to have been used to describe a gemstone that's blue or has a blue tint. It's believed that over time, the name was misused and originally referred to the stone known today as lapis lazuli.
'Sapphire' is used exclusively to describe gem-grade blue corundum. For other colours, the colour determines the name, for example, pink sapphire, black sapphire or yellow sapphire.
For corundum to be classified as gem-grade, it must be transparent and relatively free from fractures and inclusions. 
Ruby and sapphire were identified as varieties of corundum in the early 1800s. Initially, only blue was known as sapphire, while other colours, excluding red, were given various names, most of which were misleading. Green sapphire was called Oriental Peridot, yellow was Oriental Topaz.
Some sapphires can exhibit an optical phenomenon known as asterism. When the stone is held under direct light, a star-like shape appears due to the reflection off needle-like inclusions of the mineral rutile. For asterism to be fully appreciated, stones must be cut as a cabochon.
Most sapphires are heat-treated, which can improve a stone's colour and clarity.
Although Sri Lanka and Madagascar are the world's largest exporters of sapphires, they can also be found in Myanmar (formerly Burma), Australia, Thailand, India, Pakistan, Afghanistan, Tanzania, Kenya and China.
Famous Sapphires
Throughout history, sapphire has been associated with royalty and nobility. Princess Anne and Princess Diana both wore engagement rings that featured a blue sapphire.
The Stuart Sapphire and St Edward's Sapphire are part of the British Crown Jewels. The Logan Sapphire, one of the largest faceted gem-grade blue sapphires, is in the National Museum of Natural History, Washington D.C.
Other famous sapphires include the Black Star of Queensland, which before the discovery of the Star of Adam, was the largest star sapphire ever to have been mined.
The Star of Adam was found in Sri Lanka in 2015. The name comes from the Muslim belief that Adam went to Sri Lanka after being expelled from the Garden of Eden. It's believed he lived out his days on Adam's Peak, a well-known mountain near the city of Ratnapura.
The Star of India, also mined in Sri Lanka, is currently housed in the American Museum of Natural History, New York.
Sapphire Properties
Sapphire can help to focus the mind by improving concentration and clarity. It can remove mental tension and find solutions to problems, bringing inner peace and serenity.
Different coloured sapphires are associated with specific chakras. Blue sapphire is often linked with the throat chakra, promoting clear communication and self-expression.
Sapphire is believed to stimulate psychic abilities, intuition, and spiritual insight. It enhances spiritual awareness and facilitates a deeper state of meditation.
Article Photos
The first and third images in our article are stock images. The sapphire in the second photo is courtesy of James St. John. It's clickable and redirects to the original photo.
