Living up to its metaphysical reputation of being the stone of originality, labradorite has a unique composition of minerals that form its crystal structure. These properties create the stunningly beautiful visual effects this gemstone is renowned for.
Originally known as the fire stone or fire rock by the native Inuit people of Canada, Labradorite was named after the Peninsula of Labrador in Canada where it was first identified in 1770.
Labradorite is part of the plagioclase series of feldspars. It has a chemical composition of varying ratios of two separate feldspar minerals, albite (sodium aluminium silicate) and anorthite (calcium aluminium silicate) and anorthite (calcium aluminium silicate). The two minerals alternatively layer each other in microscopic flakes throughout the stone, known to gemmologists as lamellar twinning, and are planes of weakness within the crystals structure.
This particular structure is responsible for labradorite’s sheen, a colourful display of light reflected from beneath the stone’s surface, aptly named labradorescense. The spectral colours of light, ranging from red through to violet, reflected from the stone are a result of light interference from the thing layers of the feldspar minerals. Due to this gemstone’s remarkable structural quality the most significant issue which may arise when it comes to the fashioning of the rough into polished pieces for jewellery setting, is parting of the gemstone along these twinning/layered planes and may take only a small amount of force. Labradorite measures 6 oh MOH’s scale of hardness.
More commonly unearthed with a green through blue sheen, labradorite is traditionally favoured with a rich blue/violet labradorescence. Occasionally exceptional spectrum are found with flashes of the full spectrum of colour and tend to have the trade name ‘spectrolite’. When they show bright, vivid mutli-colour they can fetch a much higher price.
Bunny Bedi, owner and designer at Made In Earth, shares his experiences and knowledge on working with labradorite for over twelve years. “We take great care and consideration when polishing labradorite, cutting the stone in such a way so that the most vibrant and intense colours of the sheen are captured. Care also needs to be taken to ensure the twinning planes are not parallel to a facet or the durability of the gemstone is compromised whilst being set by our jewellers.”
It is for these reasons labradorite traditionally lends itself to a cabochon finish although when a stone is successfully faceted, the sheen can be even more intense than the soft roll of light over a domed cabochon. More recently Bunny has introduced rough pieces into his collection.
“The raw surface and organic edges bring a new life to labradorite. These stones still effectively show labradorescence and appeal to our clients to favour raw crystals instead of polished gems.”
Bunny continues, “It is also important to ensure the natural beauty of labradorite’s sheen is best viewed once the piece is being worn by its owner. Whether it’s our rich blue Madagascan gems or the multi-coloured spectrolite from Finland, each piece is carefully considered before being set.”
Despite the difficulties that may arise when polishing and setting this amazing gemstone, if treated carefully, with knowledge of its unusual crystal structure and potential for the display of beautiful and colourful visual phenomenon, labradorite truly is more than meets the eye. We think that a piece of this stunning gemstone is always a must have in your collection!