RUBY CRYSTALS - Mysore, India

A small but very nice little specimen of mica schist/gneiss studded with deep red ruby crystals. The rubies fluoresce brightly in UV light.

Ruby and sapphire are both varieties of the mineral corundum. Red corundum is called ruby, while all other colours of gem-quality corundum, including colourless, are called sapphire.

Corundum forms in metamorphic rocks. This example is from a classic Indian ruby locality.