Wonders in Tucson: amethyst stalactites
Posted by Kenneth Diede on
Tucson can be overwhelming to say the least. Among the pounds of diamonds, sapphires, emeralds and rubies, or sea-tainers of rough lapidary material, and truckloads of slabs and cabochons, it takes something pretty spectacular to stand out in a world of sensory overload. Such was the case with the amethyst stalactites from Uruguay.
Amethyst is found in abundance in many parts of the world and is spectacular because of the deep rich purple crystals and outstanding geode formations often seen as massive display pieces or individual crystals cut for jewelry. It belongs to the quartz family and has long been associated with kings and royal families. Spiritually it is believed to have an intoxicating power and promotes inner growth.
The best quality amethyst comes from Uruguay and is found underground and is igneous (volcanic) in origin. It is assumed to be about 130 million years old. The combination of both amethyst and stalactites is very rare and found in only a few places in the world. They have a core of interestingly shaped and colored agate surrounded by crystalline amethyst in varied hues of purple.
The amethyst stalactites are named after similar occurrences of limestone deposits in cave formations. Stalactites form as water laden with calcium carbonate drips from the roof of caves. As the dripping continues, layers of calcite are deposited in rings and over time they settle on top of each other creating the stalactite.
The amethyst “stalactite” is neither a limestone nor a cave formation but, rather, a tube agate that forms in the center of an agate/amethyst vug within a hydrothermal igneous formation. As the chemical composition of the ground water which fills the cavity changes, the color and the denseness of the core rings change correspondingly. Once the agate center has formed then the amethyst crystals grow on the outside surface. Stalactites are cross cut into slices to expose both the agate center and surrounding purple crystals. These sectional pieces make stunning jewelry while the geode makes a fantastic display piece.
One’s imagination is the only limiting factor in how best to enhance the natural beauty found in these amazing amethyst pieces.
