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Geode, Ethiopian Opal Inorganic, which means that it is not made by a living organism. A solid. There is one unusual exception. Native mercury is a mineral and is the only metal that is a liquid at normal temperatures. Has a regular crystal structure. The crystal structures are described as crystal systems. Made by nature which means minerals are not made, directly or indirectly, from human activity. Has a predictable chemical formula.
Ethiopian Opal Geode Opal is an amorphous form of silica related to quartz, a mineraloid form, not a mineral. 3% to 21% of the total weight is water, but the content is usually between 6% to 10%. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl and basalt. Opal is the national gemstone of Australia, which produces 97% of the world's supply.
.opal (looks like an exotic chocolate truffle)
When minerals form a flat surface it is called a face. Minerals can have many flat surfaces and when these faces join together, they form a crystal. Download the activity page on the right and create your own mineral face or even a mineral cartoon character out of the mineral faces on the sheet.