naturally occurring substances

Ore An ore is a special type of rock that contains a large enough amount of a particular mineral (usually a metal) to make it economically practical to extract that mineral from the surrounding rock. Not all minerals are found in a large enough amount in one location to make it worth it to remove the ore from the rock through a process known as mining. Ores can be mined in a number of ways, including strip mining as shown here at this uranium mine. If there is a large enough amount present, the rock will be extracted and processed in a ... Read more

Minerals Minerals are defined as solid, inorganic, naturally occurring substances with a definite chemical formula and general structure. Almost all chemical elements in the Earth’s crust are associated with at least one mineral. They vary in color, hardness, density, crystal form, crystal size, transparency, composition, location, and abundance. Some minerals are radioactive (uranophane), while others are magnetic (magnetite). Some are uncombined elements, such as gold, silver, sulfur, bismuth, copper and platinum. Certain minerals, such as fluorite (calcium fluoride), glow with a vibrant luminescence after exposure to ultraviolet light. Feldspar (a potassium aluminum silicate) and quartz (silicon dioxide) are the most ... Read more