Sapphire, the birthstone of September, is known for imparting to wearers peace, wisdom, loyalty, nobility, and faith.
While most people are referring to the blue variety of corundum crystal when they use the term “sapphire,” the gemstone is actually present in every colour of the rainbow – with the exception of red. As discussed in the blog Ruby: The Birthstone of July, the red variety of aluminum oxide crystal is actually called a ruby!
Sapphires take the term “royal blue” to a whole new meaning, with one of the most famous sapphire engagement ring belonging to none other than Princess Diane and Kate Middleton.
The padparadscha sapphire is an extremely rare type of pinkish-orange fancy-coloured variety. The beautiful name comes from a Sinhalese word meaning aquatic lotus blossom. The fetching salmon colour is highly sought after and can sell for prices higher than other sapphires.
Some sapphires can exhibit colour change depending on the type of light it is exposed to. These stones have the ability to adsorb light at two light wavelengths. So in white daylight or fluorescent light, they appear blue. Meanwhile, in incandescent light, they appear a reddish purple.
Synthetic sapphires were first introduced in 1902 thanks to French chemist Auguste Verneuil. Verneuil’s flame fusion process made synthetic sapphires more readily available for industrial uses, such as satellite communication systems, scientific instruments, and even spacecraft windows.
Famous sapphires include the likes of The Star of Adam and The Logan Sapphire. The Star of Adam is a 1,404.49-carat oval-shaped stone that shows asterism – a quality where the reflection of light by tiny inclusions gives the appearance of a 6-pointed star on the surface. The Logan Sapphire is the largest faceted sapphire at 422.99 carats. It was donated to the Smithsonian Institution in 1960 and set in a brooch by Mrs. Polly Logan, who the crystal is named after.
Modern sapphire deposits are found in Sri Lanka, Madagascar, China, Eastern Australia, Thailand and East Africa. Unsurprisingly, sapphires are often located in similar geological settings to rubies.