Glossary of watchmaking


Tourmaline | トルマリン | 电气石

A dichroic gemstone that comes in all colours of the rainbow. Some crystals are bi or tri coloured. Tourmaline has the greatest colour range of any gemstone. Tourmaline has a hardness of 7-7.5 and a specific gravity of 3.02-3.25. It is doubly refractive.