Turquoise

Turquoise stones are sometimes coated with thin layers of wax to improve their appearance. A hot point test on a tiny, inconspicuous spot can make any wax present bead like perspiration on the stone without actually touching its surface or damaging it. Destructive gemstone testing, like a hot point test, is a "last resort" for gemologists trying to make a difficult gem or treatment identification. When done carefully by a professional, these tests shouldn't lessen the value of a gem or jewelry piece. Turquoise cuff with vintage beads. Jewelry and photo by Melissa Ingram. Licensed under CC By 2.0.

Article: Destructive Gemstone Testing

Credit: Melissa Ingram