The Tourmaline Family by David Bellamy
If you ever bought a specimen that was presented as “Tourmaline”, you were told only half the truth. While the term “Tourmaline” is probably correct, the label doesn’t tell you what kind of tourmaline you have. The word “Tourmaline” describes a family of 14 minerals that are related to each other in terms of chemical composition and molecular structure.
If your tourmaline is shiny and black, it is probably “Schorl”. Schorl is sometimes tumbled into rounded, polished stones which are rather unremarkable in appearance. Schorl crystals on the other hand are quite attractive; they are long and narrow, with scoring on the long crystal faces and 3 intersecting diamond shapes at the ends. They can fetch a good price if they are undamaged.
Verdite crystal
The other common member of the tourmaline family is “Elbaite”. In its pure form, elbaite is clear and colourless and it is sometimes known by the varietal name “Achroite”, which means “without colour”.
Elbaite can come in any colour, due to the presence of metal impurities. The pink variety (known as Rubellite) and the green variety (known as Verdelite) are the most common coloured varieties of elbaite. Good quality stones can command high prices when they are faceted for jewellery. Lower quality stones are sold as attractive beads of various shapes and as tumbled stones. A particularly bold, electric blue version of elbaite is known as Paraiba Tourmaline (after Paraiba, Brazil) and good stones cost a fortune.
Tourmalines, especially elbaite, make attractive gemstones and it’s a shame that they aren’t as well known as the more familiar gemstones. On the other hand, less demand keeps the prices down for collectors of nature’s artistry.
Come to the Club’s annual show September 17,18 2011 to see more tourmalines, crystals, beads and faceted stones
