Unheated Gem
Unheated Gem
Red Spinel Gemstones
Some of the rarest gems in the world are spinels, even if many of them were once believed to be rubies or sapphires. For example, the enormous Black Prince's Ruby that adorns the Imperial State Crown of the United Kingdom is actually a spinel. But in fact all natural spinel are fairly rare, and that's why they can be difficult to find in jewelry stores. It is also, paradoxically, why the prices for spinel are still reasonable.
It was not until the nineteenth century that the structures of the many natural forms of spinel were finally recognized, as well as the astounding beauty and clarity of it range of colors.
Natural spinel is a very fine gemstone indeed, with many characteristics that make it the near-equal of ruby and sapphire. Spinel is a magnesium aluminate, typically colored by chromium and iron and, occasionally, cobalt. It is very hard (8 on the Mohs scale, compared to 9 for ruby and sapphire), and it forms as a cubic crystal like a diamond. Spinel occurs in octahedral crystals but fortunately has very poor cleavage (unlike diamond, which has perfect cleavage). Due to spinel's very good dispersion, gem spinels can possess vivid fire, and the intensity of spinel color is in part due to the fact that spinel is one of the few singly refractive gemstones (the others being garnet and diamond).
Almost all the ruby and sapphire in the market has been heat treated to improve color and clarity. But spinel is a gem which is never treated. That makes spinel an unusual gem in today's market.
Burma and Sri Lanka are the traditional sources for fine spinel, though the Burmese material is generally recognized as superior. But the supply is very limited and is not sufficient to supply the retail jewelry trade. So many jewelers simply don't stock spinel and thus the market doesn't promote it. This can make natural spinel quite difficult to find. But it also means that prices are surprisingly reasonable. Compare the prices for unheated ruby and sapphire (if you find them)!
Recently some high quality African spinel has come on the market, with some pieces in good sizes. We have found some excellent spinel from Tanzania in red, pink, violet, and blue; and occasionally in unusual colors such as orange and purple. The supply of Burmese spinel is limited, but the material is generally of very high quality.
Red is the most famous color in spinel, but spinel occurs in a range of colors, including pink, violet, orange, silver and blue. The red and pink spinel are the most prized, followed by the lavender and blues. Any spinel over 2 carats is rare, and good stones over 3 carats count as very rare.
About the Author
GemSelect is a leading online dealer in fine gemstones, including red spinel, sapphire, garnet, tourmaline and zircon. View spinel gem photos
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Africa Gems
The traditional sources for colored gemstones are in Asia and South America, especially Burma, Sri Lanka and Brazil. But these days Africa is generating most of the the excitement in the gems world, with about 70% of colored gems in the market originating from Africa.
Everyone knows Africa as the source for diamonds, but the colored gemstone business is increasingly important, even though colored gem production is spread across small mines in more than half a dozen countries. The main gemstone producing countries are in southern and eastern Africa, stretching from Namibia in the southwest through Zimbabwe, Mozambique, Malawi and Tanzania to Kenya in eastern Africa. Madagascar, the large island off the coast of Mozambique, is geologically part of this same gemstone-rich area, known as the Neoproterozoic Mozambique Belt.
Colored gemstone production from the African mines is constantly changing and smart buyers have learned to "buy it while you can" since gems that are plentiful one year may hardly be found the next year. This happened with the fine spessartite garnet from Namibia, for example. While there is still some supply from Namibia, it is difficult to find and most of the better spessartite is now coming from Mozambique.
The most important producers recently have been Tanzania, Mozambique and Madagascar. Madagascar is famous for recent discoveries of ruby and sapphire, though a number of other gemstones have been found, including tourmaline, aquamarine, chrysoberyl, andalusite, apatite, citrine, iolite and kyanite. Tanzania has enormous potential and gemstone mining there already employs more than a half of million small-scale miners throughout the country. Tanzania is especially famous for tanzanite, but this year we've bought very fine Tanzanian spinel in large sizes, marvelous rhodolite and tsavorite garnet, and some unique colors in unheated zircon.
Mozambique is producing excellent tourmaline in a wide range of colors, and we have also bought fine spessartite and red garnets in impressive sizes. Mozambique has recently become famous for its high quality paraiba tourmaline, and most of the world supply of paraiba is now coming from Mozambique since the Brazilian supply is so limited.
Nigeria, the large west African nation, is the one important gemstone producer not in the Mozambique Belt. Nigeria has produced respectable blue sapphire as well as large quantities of fine tourmaline. Nigeria is also known for pyrope and almandine garnet, aquamarine and topaz. Mali, also in west Africa, is famous for the rare Mali garnet, a hybrid of grossularite and andradite garnets.
Given the state of development in most of the producing countries, we expect African gemstone production to increase in the coming years. But the supply from most of these mines is very limited, and in our experience one has to be an opportunistic buyer when supply is plentiful.
About the Author
GemSelect is a leading online dealer in fine gemstones, specializing in African gemstones such as tsavorite garnet, tourmaline, sapphire and tanzanite. Fine Africa gems
