(Last Updated on : 22-12-2012)
Pure spinel is white, but impurities often give it a wide range of colours. Spinel is available in many colours like, yellow, brown, black and violet. The name Spinel is derived from a Latin word meaning 'thorn' for which the shape of this gemstone might be held responsible.
Almost all the colours of spinel are used in jewellery, but the most valuable and popular colour is the deep red. These red gems closely resemble rubies, and the two may be difficult to distinguish. In fact, until the late 19th century, there was no distinction between ruby and red spinel, as they look identical and are found in the same localities. Nowadays, distinctions can be made through hardness and x-ray tests. Many famous old 'rubies' were found to be Spinel. The enormous 'ruby' that forms the centrepiece of the royal crown of England was determined to be spinel as well. Spinel is easily synthesized, and can be made into any colour by adding impurities. It is made to resemble gems such as diamond, sapphire, and zircon. When purchasing spinel gems, one must be careful to make sure that the spinel is natural and not synthetic. Most colourless spinels on the market are synthetic, as are some red ones. Spinel is usually cut into gems for use as jewellery. The deep-red variety is known as ruby spinel. This is the most prized form. The opaque, black variety, known as pleonast, is perhaps the most popular black gemstone
. Spinel is also cut as cabochons, and occasionally exhibits weak asterism.
Spinel naturally occurs as octahedral crystals. In well-shaped red crystals, the gem cutter may decide to even out the crystal, making it a perfect octahedron. These "crystals" may be worn in jewellery without any further faceting.
Spinel has a very bad reputation of deceiving people as rubies for centuries. Many royal famous ornaments are mistaken to be studded with real rubies when Spinels were actually used. The most famous "Black Princes" ruby, which decorates the Imperial State Crown of England, actually bears a 170 carat Red Spinel. In the 16th century Spinel gained its individual status as a gemstone in Asia.
There are different varieties of the Spinel. The names can be mentioned as Ruby Spinel i.e. ruby-red variety of Spinel, Rubicelle is the other variety, which is yellow to orange variety of Spinel, Balas Ruby is the pink to pale red variety of Spinel, and Almandine Spinel is the violet variety of Spinel. Blue Spinel can be mentioned as the light to dark blue variety of Spinel while Pleonast is the black variety of Spinel, Picotite is the brown variety of Spinel, Gahnite or Gahnospinel is the greenish or bluish i.e. zinc-rich variety of Spinel. Sapphire Spinel is the false name describing blue spinel as well.
There are also some synonyms of Spinel that can be mentioned as Spinell is a synonym of spinel, Spinel ruby is a synonym of ruby spinel, Piconite is a synonym of picotite, Flame Spinel is a synonym of rubicelle, and Pleonaste is a synonym of pleonast
Pinkish red transparent gemstone is the jewellers and collectors most favoured item for centuries. Its durability and hardness are perfect for its usage in jewellery making. Spinel is often found in oval, round and cushion shaped. The features of spinel like isometric crystal system, unclear cleavage, glassy lustre and white streaks are essential part of the stone. This gemstone was formed after a basic rock in the earth's crust had gone through a metamorphic change. The top layer of the earth's crust is where the Spinel is mostly found like in the gemstone bearing gravels and in the lime stones.
Burma, Sri Lanka, Tanzania and some parts of Western Europe are the places where Spinel is found the most. Spinel has become very rare these days and because of this reason its demand is decreasing day by day as people hardly get a chance to see and appreciate the magnificent stone.