This article was featured in the March 2000 issue of Discovery Calendar Gems of Advice by Colleen Wilson A methyst, emerald, carnelian, jet. Beautiful jewelry is the stuff of princely quests and dragons' hoards. But like all earthly treasures, Time will corrupt it unless the charms of conservation are used. Turquoise, topaz and lapis lazuli can change colour or fade, and opals can crack if exposed to prolonged sunlight.
Ultraviolet radiation can cause white zircon to revert to brown.
On the other hand, in the heat of a dragon's fiery breath, amethysts may change colour, and garnets and sapphires fracture. Having pirates bury your treasure will avoid both light and heat, but it is difficult to control humidity on the Spanish Main. Marcasite is sensitive to high humidity and aquamarines can crack in water. Steel beads will rust. Diamonds can scratch other diamonds.