When paraiba tourmaline first reached the market in the early 1990's, it led to a tremendous interest in copper-bearing gemstones. We receive many emails from customers asking whether particular gems in our inventory are copper-bearing. There seems to be a perception in the market that a gem containing traces of copper is inherently valuable. But is it reasonable to think that?
It's not like copper is a particularly valuable mineral. The average American home is said to contain over 400 pounds of copper -- in the plumbing, wiring, appliances, cookware and so on. So if you really want copper you don't need to leave home to find it. Your home is significantly copper-bearing, as are the coins in your pocket.
As far as minerals go, there are about 160 different minerals containing copper. Even among gemstone-grade minerals, there are many copper-bearing varieties to choose from. They include malachite, azurite, turquoise, chrysocolla chalcedony quartz, larimar, oregon sunstone and, of course, paraiba tourmaline.
Many of these copper-bearing minerals are quite inexpensive. We sell nice turquoise for less than three dollars a carat. Azurite is even cheaper, though lapis lazuli is usually preferred for its better color and hardness. Chrysocolla, another soft and inexpensive cuprian stone, is even cheaper than turquoise.
In fact the only truly expensive copper-bearing gemstone is paraiba tourmaline. Since there are lots of other copper-bearing gems, why is paraiba tourmaline so pricey? It can't be just because its copper-bearing.
Paraiba tourmaline is valuable because of its unique and outstanding color, and the fact that it is extremely rare. It wouldn't matter how much copper there was in its composition if it didn't have that neon blue-green glow.
But isn't it precisely because paraiba tourmaline contains copper that it has that outstanding color? Well, yes and no. The distinctive blue-green color is characteristic of copper oxide. That's why turquoise has it's wonderful color, and it's why the largest copper structure in the world, the Statue of Liberty in New York, has acquired a marvelous green patina. But paraiba tourmaline is not only colored by copper, it is also colored by traces of manganese. Gemologists believe it is the combination of copper and manganese that is responsible for paraiba tourmaline's unusually vivid color.
It's also worth keeping in mind that paraiba tourmaline is the only transparent gemstone that contains copper. Other copper-bearing gems, such as turquoise, have that lovely blue-green characteristic of copper, but the effect is quite different in an opaque gem.
Most of the paraiba tourmaline available in the market right now is from Mozambique. But Mozambique also produces a wide range of terrific tourmaline colors. Don't assume that just because some tourmaline is from Mozambique that it is may be the especially valuable copper-bearing variety. It is the vivid paraiba color that makes some tourmaline especially valuable, not simply the presence of copper in its composition. Pink or green or red tourmaline from Mozambique is very unlikely to contain copper. But even if it did, it wouldn't increase its value, since those colors are not especially rare.
- First Published: February-04-2008
- Last Updated: September-23-2009
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