Stability

Stability is a term that describes how well a diamond resists temperature changes and chemicals. Diamonds are very stable. They’re invulnerable to virtually all acids, for one thing. The cutting process generates a lot of heat, but diamonds usually endure intact. Situations that are more threatening to a diamond’s stability are those that involve sudden and extreme temperature changes. Those changes can cause thermal shock, which can create new fractures and cleavages or cause existing ones to spread.

Diamonds will burn at about 1562°F (850°C). House fires and jewelers’ torches can reach that temperature. If you work in the industry long enough, you’ll probably see diamonds that have been burned. They look white and cloudy.

Sometimes a burned diamond just looks dirty, and a jeweler will try to clean it. But it’s not dirt, and cleaning won’t improve its appearance. The burn actually marks the diamond’s surface, so repolishing is the only way to restore its beauty. Usually this can be done without difficulty, and with little weight loss.

This diamond suffered thermal shock when it was exposed to a sudden and extreme change in temperature.