Agate, Amethyst, Citrine, Jasper, Rock Crystal, Rose Quartz—all things of beauty, of course, but what else do these minerals have in common? Why the fact that they all are variations of quartz! Add a little of this or a little of that to silicon dioxide, and colorful beauty appears. Of course, add a little bit of something else, and you're likely to get a rock as ugly as sin.
Natural characteristics of quartz have long been taken advantage of by
pre-modern peoples. It's extremely hard and fractures much like thick glass, a
so-called conchoidal fracture. As a result, non-flawed quartz makes ideal material for
the manufacture of arrowheads. And all fans of history know that another form of
silicon dioxide, flint, was struck with steel to produce a spark--a spark to start a
fire or to fire a flintlock musket. For something almost magical, search among our
desert gravels until you find a couple of smooth, egg-sized pieces of quartz. Grind
them together in a very dark place—and watch a mystical glow appear at the
contact!
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
Quartz Mineral Data
USGS "Magic" Quartz Pebbles