A Tennessee native, Chase Pipes enjoys sharing his love of geology and history with the general public at the Smoky Mountain Relic Room in Sevierville, Tennessee. Each year, Chase Pipes goes to Arizona for two months to participate in the Tucson Gem, Mineral, and Fossil Showcase. He described the event in a Knoxville News Sentinel article, saying the showcase features everything from “five-ton amethyst geodes to 800-pound meteorites.”
Geodes, found across the Americas, are rocks with an interior cavity lined with minerals. They originate as igneous rock gas bubbles.
Amethyst geodes from Parana Continental Flood Basalt Province in Brazil start as lava. Gas bubbles rise to the surface and become trapped as the lava quickly cools. This results in cavities in the hardened lava bubbles.
Over time, saltwater in an aquifer below is forced upward and into the porous basalt cavities. The saltwater contains minerals, such as silica. Over hundreds of thousands of years, a combination of cooling and pressure release provides the conditions for crystal growth.
The types of minerals trapped in the cavity determine the nature of the crystals, which include celadonite, agate, quartz, and amethyst. The striking purple color of “amethyst cathedrals” makes them popular with collectors around the world.
Geodes, found across the Americas, are rocks with an interior cavity lined with minerals. They originate as igneous rock gas bubbles.
Amethyst geodes from Parana Continental Flood Basalt Province in Brazil start as lava. Gas bubbles rise to the surface and become trapped as the lava quickly cools. This results in cavities in the hardened lava bubbles.
Over time, saltwater in an aquifer below is forced upward and into the porous basalt cavities. The saltwater contains minerals, such as silica. Over hundreds of thousands of years, a combination of cooling and pressure release provides the conditions for crystal growth.
The types of minerals trapped in the cavity determine the nature of the crystals, which include celadonite, agate, quartz, and amethyst. The striking purple color of “amethyst cathedrals” makes them popular with collectors around the world.
