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Black Spinel

In Sweden the black Spinel is uncommen, black Onyx is used instead. But the black Spinel have a much deeper blackness, a glas-like face and is further moore a much harder mineralen. Therefore its perfect in finger rings.

 

Size: de list below

 

In stock: 1 of each size except 2 of 16x13

 

Price:  USD 5.60 - 10.10

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Spinel is the magnesium aluminium member of the larger spinel group of minerals. Its hardness is 8, its specific gravity is 3.5-4.1 and it is transparent to opaque with a vitreous to dull luster. It may be colourless, but is usually various shades of red, blue, green, yellow, brown or black. There is a unique natural white spinel, now lost, that surfaced briefly in what is now Sri Lanka. Some spinels are among the most famous gemstones: Among them is the Black Prince's Ruby and the 'Timur ruby' in the British Crown Jewels, and the 'cote de Bretagne' formerly from the French Crown jewels. The Samarian Spinel is the largest known spinel in the world, weighing 500 carats (100 g).

The transparent red spinels were called spinel-rubies or balas rubies. In the past, before the arrival of modern science, spinels and rubies were equally known as rubies. After the 18th century the word ruby was only used for the red gem variety of the mineral corundum and the word spinel became used. "Balas" is derived from Balascia, the ancient name for Badakhshan, a region in Afghanistan. The Badakshan Province was for centuries the main source for red and pink spinels.

Spinel has long been found in the gemstone-bearing gravel of Sri Lanka and in limestones of the Badakshan Province in modern day Afghanistan and of Mogok in Burma. Recently gem quality spinels were also found in Vietnam, Tanzania, Kenya and Madagascar. Spinel is found as a metamorphic mineral, and also as a primary mineral in rare mafic igneous rocks; in these igneous rocks, the magmas are relatively deficient in alkalis relative to aluminium, and aluminium oxide may form as the mineral corundum or may combine with magnesia to form spinel. This is why spinel and ruby are often found together.

 

 

 

 

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Latest update: 22 september 2015