Corundum gone red with chromium. The same mineral as sapphire, and nearly as hard as diamond.
The aesthetic
Ruby is corundum coloured red by chromium, and every other colour of the same mineral is called sapphire, so the line between them is drawn by tradition rather than chemistry. It grows as stubby six-sided barrels, and the finest colour, a slightly purplish red, fluoresces in sunlight so that the stone appears lit from inside. Rough material with fine rutile needles running through it produces a six-rayed star when domed.
The dynamic
Ruby is associated with passion, courage and vitality, and has been a stone of rank and of the heart in nearly every culture that has had access to it.
Some variations
- star ruby
- ruby in zoisite
- ruby in fuchsite
- burmese ruby
- raw ruby crystals