Chalcedony is a natural microcrystalline quartz, and therefore never transparent. Used mostly as an ornamental gem, some of its better-known varieties are carnelian, sard, bloodstone, onyx and sardonyx, agate, and fire agate. Common translucent chalcedony occurs in a wide range of natural colors, with some of the more current discoveries made in blues and lavenders. With chalcedony’s recent popularity—thanks to its pastel colors and inexpensive price range—it never hurts to be reminded that chalcedony is easily colored by dyes: In fact, most of what is called “black onyx” is actually dyed black chalcedony.

Maxam Magnata, of Tucson, known for its promotion of natural colorful drusys as well as titanium- and platinum-coated drusys, will be featuring color-enhanced Sea Blue Chalcedony at Tucson in February. According to Magnata, this is the first time a chalcedony has been permanently colored this shade of blue. Prices for the new chalcedony should range from $1.50 to $5 per carat. For more information, visit www.BlueChalcedony.com, or call (520) 622-1964.