All natural spinel gems are fairly rare and that is why they can be difficult to find in jewelry stores. It is also, paradoxically, why the prices for spinel are still reasonable. When many people think of spinel, they usually think of synthetic spinel material used in low-end jewelry, such as triplets, gemstone class rings and birthstone jewelry. However, the natural gemstone known as spinel is actually a very fine gemstone with many characteristics equal to that of ruby and sapphire.
Spinel is composed of magnesium aluminates typically colored by chromium and iron. Spinel is found in a wide range of pastel shades, which include many pink variations, including, grayish-pink silver-pink to coral-pink and rose-pink. Red and pink spinel gems are the most valuable and highly sought-after. Pink spinel is very rare, especially vivid red-pink spinel. Most purple and violet spinel is pale, but there are many fine deep purple spinel gems available. The beauty of spinel color intensity and purity of is mostly owed to the fact that spinel is singly refractive, like garnet and diamond (most gemstones are doubly refractive).
Purple spinel has a hardness of 8 on Mohs scale and it has an excellent overall durability rating owed to its poor cleavage, unlike diamond which can be split by a single blow due to perfect cleavage. Spinel also has very good fire and dispersion. Spinel is difficult to find in large sizes, so any gems weighing over two carats is quite rare. Spinel over three carats is extremely rare. Due to the extreme density of spinel, a 2 carat spinel will appear much smaller than another gem type of the same weight, sometimes even equivalent to that of just a single carat gemstone of another type. Today, most pink spinel is mined from Myanmar (Burma), Tanzania and Sri Lanka (Ceylon), with Burmese material generally recognized as the most valuable and superior spinel source.
However, the supply for natural spinel is very limited in Burma; in fact, because there is not enough spinel available to be mined for sufficient commercial quantity, retail jewelry trade, including jewelers and jewelry stores, normally do not carry spinel in their stores and shelves. This is why most spinel gem seekers will have to look towards online gemstone dealers when shopping for spinel gemstones, and as a result of the lack of marketing and retail exposure, spinel remains mostly unheard of by the general public.