History�and General Information of Natural Spinel Gemstone

The word spinel either comes from a Latin word �spina� that means �thorn� or from a Greek word 'spinther' that means �spark�. Estimates on dates suggest that till the 1800�s, the spinel gemstone crystal was thought to belong to the corundum family. This collection gem has always been overshadowed by its more opulent cousins and precious stones - the ruby and the sapphire. In fact, the transparent natural red spinels are called spinel rubies or balas rubies (a name based on the place where the crystals were first found i.e. Balascia, the ancient name for Badakhshan in Afghanistan).( Image: Trillion Cut Red Spinel)

The red� spinel was often mistaken for an actual natural ruby in ancient times and it was only on close inspection that once could tell the difference. The fame, brilliance and spectacular history of the spinel gemstones are extremely interesting. The Black Prince�s ruby, which is a part of the British crown jewels in London, is a spinel. The Timur Ruby (over 350 carats) that graces the front of the Imperial State Crown of England is also a spinel. Historical data suggests that this unique Timur Ruby spinel has the names of its six owners in whose possession the precious gem ever stayed. The names start from Shah Jahangir (1612) and end with Shah Durr I-Dauran (1754) inscribed on it. Mark Smith of Bangkok owned an extraordinary and rare cat�s eye spinel. (Image:�Red Spinel Crystal)�

In spite of the reputation that the spinel gemstone enjoys as a dealer�s gemstone and the references that it has in history, a relatively small number of consumers are aware of this fascinating gem. With the increasing popularity of colorful gemstones in fashion jewelry, perhaps more consumer would desire to buy this gem.�(Pic: Pear�Shaped Pink Spinel)�

Compostion

The chemical formula of the genuine spinel is a manganesium aluminium oxide (MgO Al2 O3). Its specific gravity is 3.58 to 3.64 and the refractive index ranges between 1.712 and 1.80. The hardness of this�gemstone on Mohs scale is 8. (Image: Earrings made with spinel)

Physical Properties

Spinel Color

This gem is found in many colors ranging from red, pink, violet, purple, green and indigo to blue. Mineralogists state that the red and natural pink spinel derive�its color from the trace element and mineral chromium, while the orange to purplish gems owe their color to the trace elements and minerals like iron and chromium. (Pic: Black Spinel Rough and�Polished)�

Initially, the natural blue spinel gem was believed to owe its color to iron however it has been found to have traces of cobalt too. In fact, it is now known that the lesser the amount of iron present in the gem, the better the blue color.

Star spinels and color change spinel varieties are also found but these are not easily available. These special gems are limited to being a collector�s item. The ark green variety is called Gahnospinel, the blue to dark blue variety is called Gahnite, the black variety is called Hercynite and the dark red to black variety is called Galaxite. (Pic: Blue Spinel Rough)�

Cut

Spinel�is usually faceted in an oval cut. The deep shape oval is one of the favorites for fashion jewelry like spinel earrings, spinel rings and the like. The natural purple spinel can be doubled with the small diamonds to design a majestic pendant too. The pretty pink spinel gemstone can also be used in a similar manner since the pink spinel gem is a unique color. (Image: Purple Spinel�Rough and Polished)�

Carat

Though large sizes up to the weight of 10 cts can also be found, most of the genuine spinel gemstones that are used in spinel jewelry these days weigh between 0.10 carat and 3ct. (Pic: Lot of Spinels)

Clarity

The spinel gemstone is clear, flawless and transparent. Small inclusions may also be seen only after adequate magnification.�

Price, Cost�and buying of spinel Gemstone

The most rare and valuable amongst the spinels is the red spinel, followed by the cobalt blue spinel or the cobalt spinel. Though the natural spinel gemstone is a beautiful gemstone it has not yet reached the epitome of its potential in terms of popularity. It is usually sold as an alternate to the ruby. The price of a fine quality natural spinel gem can range anywhere from $10 per carat to $1000 per carat. (Pic: Cushion Cut Spinel Gemstone)

Markets and Producers

Treatments

Spinels that are found in the market are mostly untreated since they are almost always completely devoid of flaws and completely clean. Some spinels, however, are heat treated. They are heated to enhance the color of the natural gem to a deeper hue.(Image: Red Spinels in rough form)

Simulants

The common simulants of the natural spinel are synthetic spinel, zircon, aquamarine, tourmaline, cobalt glass, garnet, ruby and sapphire.

Interesting Trivia and other spinel facts

Legend has it that the Samarian spinel adorned the neck of the biblical golden calf. This was made by the Israelites while Moses was receiving the Ten Commandments. This blood red, semi-polished gem stone weighs 500 carats and has a hole in it. It is the largest known spinel in the world and is presently housed at the National Jewelry Museum of Iran, in Tehran. Needless to say it is among the crown jewels of Iran.{Pic: Pink Spinel gemstone and rough (below)}

Reference

1) Webster
2) Gemmology by Peter G.Read
3) Handbook of Gem Identification -�� Richard� T.Liddicoat, jr
4) Gems and Crystals - From the American� Museum of Natural History - Anna S.Sofianides� and George E.Harlow.