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.Know More
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
Marble is a type of metamorphic rock found worldwide where geologic conditions are optimal to transform sedimentary carbonate stone such as limestone or dolomite. The mineral grains are recrystallized under substantial heat and pressure, creating white and colored crystalline rock that can be cut and highly polished.Full Answer >
Limestone types may be formed either inorganically or biochemically and include coral reefs, chalks, coquina and oolitic limestone. Limestone is composed of calcite and makes up approximately 10 percent of all sedimentary rocks.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 >
Marble is a metamorphic rock formed from limestone. Changes in the limestone's chemical properties due to external forces can result in the creation of marble.Full Answer >