Geodes are mostly found in deserts, volcanic ash beds and areas with limestone throughout the world. In the United States, common geode sites include Arizona, California, Iowa, Nevada and Utah. The most abundant geode sites in California are Riverside and Imperial counties.Continue Reading
According to DesertUSA, one of the most popular geode areas is known as the Hauser Geode Beds, which are found at Wiley Well in Imperial Valley, California. Other well-known places with the finest concentration of geodes are the Cinnamon Geode Beds and the North Black Hills Geode Beds.
Geodes are found in volcanic rocks and sedimentary rocks such as limestone and dolomite. They form in sedimentary rocks when cavities are dissolved by ground water and minerals are deposited again as crystals. Additionally, they form in pre-existing concretions and spaces caused by expansion of rocks due to internal fluid pressure.
Geodes typically have minerals like carbonates, a crystal lining of quartz and an outer shell of chalcedony. Their size often reaches over a meter in diameter. Geodes made of dolomite and calcite have been found in sedimentary rocks in the Muswellbrook-Singleton region in New South Wales. According to the Australian Museum, volcanic geodes made of chalcedony, calcite, agate and amethyst quartz have been found in several regions in Queensland, New South Wales and Victoria.Learn more about Geology
Geodes are available for sale from retailers and wholesalers such as Amazon.com, BestCrystals.com, BuyGeodes.com, PikesPeakRock.com and GemCenterUSA.com. Amazon.com sells retail geode kits, containing small, unbroken geodes, geode information and breaking instructions. BestCrystals.com sells already opened, display-ready, larger cathedral and other styles of geode, including amethyst, agate and quartz geodes.Full Answer >
Granite makes up a portion of the Earth's crust, and exists in virtually all land areas around the world. Granite forms the middle layer of the Earth's core, along with several other minerals and rocks. It forms the basis of the continental crust, and it also exists in seabeds.Full Answer >
Geodes can occur in both igneous and sedimentary rocks. Bubbles in lava can form cavities in igneous rocks as they cool, while animal burrows, desiccated tree roots or mud deposits in sedimentary rocks may create similar hollows. When mineral-rich water flows through these voids, it can leave behind deposits that eventually form the crystal structure of a geode.Full Answer >
Examples of nonmetallic minerals include sulfur, phosphorus, iodine, carbon, selenium, limestone, dolomite, gemstones, clay and mica. Nonmetallic minerals are minerals that do not contain metal. Physically, they are very volatile and have low elasticity. Chemically, they have high ionization energy.Full Answer >