Tourmalines are borosilicates with a very complex structure. The colours are caused, among other things, by tiny amounts of foreign matter and trace elements. Because of the complex structure of this gemstone, it exists in an almost endless number of varieties and colours depending on where it developed.

There is something fascinating about this individuality, for practically each deposit has produced its own kind of tourmaline. With a little luck, now and then one may come across a really special highlight in the trade: a chrome tourmaline. That is the name given to the emerald green variety from Tanzania, coloured by vanadium and chrome. Its colour is extraordinarily beautiful, and amazingly similar to that of a fine emerald, which, after all, is among the most expensive gemstones in the world.