An unusually large piece of dravite tourmaline from our collection of crystals, rocks and minerals. Dravite is a brown variety of the mineral tourmaline that's rich in sodium and magnesium. When heated its colour becomes lighter and although relatively common, it tends to be overlooked because it's not one of the most colourful minerals and the formations in which it occurs can be fairly uninteresting.
This variety of tourmline was first documented in a book on mineralogy written by an Austrian professor in 1884. It was named dravite after the Drava river in Austria and Slovenia. Dravite can be a lustrous mineral that is known to exhibit impressive crystallisation but it's very rarely used as a gemstone.
Tourmaline is the name given to a family of minerals many of which have a different composition but all share the same basic crystal structure. Dravite tourmaline is relatively hard and grades 7 to 7½ on Mohs scale of mineral hardness.
This piece of dravite is well included with silvery specs of mica and it's the only piece of brown tourmaline that we have in our collection.
Tourmaline is one of the modern birthstones for the month of October with the other being opal.
Weight (grams): 205
Size (cms): 6.2 x 3.9