Step 2: Advanced Gemology

Lesson 6

Gemstone heat treatments can turn mediocre pieces into items of great beauty. Heating a gem to a specific temperature and then cooling it is a common procedure in the gem world. This can improve a gem’s color and sometimes even its clarity. Such treatments do a number of good things for our budgets as well as the environment, since more rough material coming out of the ground becomes useful for its beauty. Here you’ll find a summary of the most commonly used gemstone heat treatments and tools as well as some safety tips for novice gemologists and gem cutters.

A Note On Corundum Heat Treatments

Ruby and sapphire are some of the most commonly heated gemstones. However, these gems aren’t?discussed in this article. A standard electric oven can’t reach the temperatures needed to treat these corundum gemstones. A special oven with platinum elements or another method of heating is needed. Heating corundum also requires controlling the atmosphere inside the heating chamber. Even with this special equipment, there are many subtle variations in technique. There’s no simple approach to heating all the varieties of corundum. Gem material from different localities needs…