Fluorite Octahedron – Illinois

Fluorite octahedron crystals of varying colours from Illinois, USA. These individual crystals are available in various sizes around 7 mm in for small crystals and around 15 mm in for larger crystals and while they are genuine fluorite, they have been cleaved into these octahedron shapes which is done due to the fluorite minerals points of cleavage which allows it to ‘break’ in four directions. Despite this, they still exhibit, excellent, almost gem quality clarity with very minor inclusions. Such crystals from Illinois are now difficult to come by these days as the fluorspar mines in the areas have long since ceased operations, causing supply of crystals to be exhausted. The crystals are available in three colours, clear, purple and blue, with the purple and blue colourations being attributed to various impurities mentioned earlier, and all are translucent, allowing quite an amount of light to pass through which further enhances the gem quality. It is understood that these particular pieces of fluorite formed during the Jurassic period, 150 to 200 million years ago, when water within the earth percolated (flowed) through rock which formed during Mississippian stage of the Carboniferous period, some 358.9 to 323.2 million years ago, when water containing the fluoride as a dissolved chemical from deep within the earth were deposited within faults and fractures within the local country rock (limestone in this case), the conditions were ideal, allowing the fluoride to crystallise into fluorite veins and deposits. Due to the small size of these crystals, they come supplied in a small x4 magnifier box and label for ease of viewing.