Fluorite, also known as fluorspar, is a vibrant gemstone loved for its diverse palette of colours and intriguing geometric form. Typically found as well-shaped cubic or octahedral crystals, this gem comes in a wide variety of colours. When polished, fluorite showcases a beautifully translucent, soft lustre, making it a popular choice for jewellery.
Fluorite's uniqueness extends to its phenomenon of fluorescence. It's famed for glowing in a mesmerising blue-violet colour when exposed to ultraviolet rays, a trait so unique it gave the term 'fluorescence' its name. Alongside its glassy texture and perfect cleavage, these distinct attributes make fluorite a gemstone with great visual appeal and a dash of wonder.
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Fluorite is also commonly known as 'fluorspar', a term that encompasses the various grades of this mineral used in different industries, including acid, ceramic, and metallurgical grade fluorite. A specific variety of fluorite, exhibiting striking bands of yellow and purple, is called 'Blue John'. Despite its distinctive characteristics, fluorite can sometimes be misidentified as other colourful minerals like amethyst or calcite.
The colour range of fluorite is extensive, ranging from colourless to black. The gem can also be found in shades of green, purple, pink, yellow, and red. The vibrant, intense hues of fluorite are naturally occurring, caused by various impurities within the crystal structure. It's also worth noting that the colour of fluorite can sometimes be altered or enhanced by exposure to heat or hydrocarbons.
Fluorite is a globally found mineral, with major deposits in several countries including Brazil, Britain, Canada, China, Germany, Mexico, and the USA. These regions are known for their significant fluorite sources, contributing largely to its global availability.
Fluorite, or calcium fluoride, belongs to the halide minerals group, distinguished by their isometric crystal structure that forms well-shaped cubic crystals, often appearing in octahedrons.
Fluorite's tendency to fluoresce under ultraviolet light is one of its most unique properties, so much so that the term 'fluorescence' was coined from it.
Its cubic crystals often exhibit perfect cleavage, which allows for the smooth shaping of the crystal into a perfect octahedron.
Historically, artisans in Ancient Egypt and China utilised large fluorite crystals for carving and creating ornamental objects. A fascinating instance of this is the Blue John variety of fluorite, extensively used for carving decorative bowls and goblets.
Despite its stunning colours and unique properties, fluorite is not a rare mineral and can be easily obtained. Its value varies based on its grade and intended use, with different grades being used in chemical, ceramic, and metallurgical applications, among others. Optical grade fluorite, particularly specimens with exceptional clarity, can fetch a high price in the market.
Quality in fluorite is determined primarily by its colour intensity and clarity. Vibrantly coloured fluorites with minimal fractures and inclusions are more desirable. However, because of its perfect cleavage, fluorite may often be found with its edges or sections chipped off.
Fluorite's colour can sometimes be altered by exposure to heat or hydrocarbons. But this treatment is not common because it is already often naturally vibrant.
Although synthetic versions of fluorite exist, they are not commonly encountered in the gemstone market as natural fluorite is not rare. Identifying real fluorite involves checking for its distinct properties such as its ability to fluoresce under UV light and its perfect cleavage.
Fluorite is relatively soft, with a hardness rating of 4 on the Mohs scale, and should therefore be handled with care. Avoid physical activities while wearing fluorite and refrain from using abrasive cloths for cleaning, as even light friction can damage the stone's polish. Avoid wearing fluorite with other gemstones or metals as they can scratch and damage fluorite. For cleaning, clean fluorite with a soft cloth and warm soapy water if needed.
Fluorite has been used by many cultures over the centuries. The Egyptians and Chinese, for example, used large fluorite crystals for carving decorative and ornamental items. The British variety of fluorite, Blue John, has been historically used for making unique ornamental pieces such as bowls and goblets.
Given its wide range of colours, fluorite can be mistaken for other gemstones like amethyst, emerald, or even tourmaline. However, its unique physical properties, such as its lower hardness, fluorescence under UV light and perfect cleavage, help in distinguishing it from other gems.
While fluorite doesn't have related gemstones in the traditional sense, its wide colour spectrum allows it to visually resemble a variety of different stones. Depending on its colour, it could be visually similar to emerald, amethyst, or even ruby. However, in terms of composition and structure, it remains a unique gemstone without any directly related varieties.
