Minerals Minerals Minerals are substances that meet five

Minerals

Minerals • Minerals are substances that meet five requirements: • naturally occurring • inorganic • solid • definite chemical composition • ordered internal structure

Mineral Characteristics (The following questions can help determine if a substance is a mineral or not. ) • • • Is it formed naturally? Is it nonliving or inorganic? Is it a solid? Does it have a definite chemical composition? Does it have an ordered internal structure?

• "Naturally occurring" means that people did not make it. Steel is not a mineral because it is an alloy produced by people.

• "Inorganic" means that the substance is not made by an organism. Wood and pearls are made by organisms and thus are not minerals. • "Solid" means that it is not a liquid or a gas at standard temperature and pressure.

• "Definite chemical composition" means that all occurrences of that mineral have a chemical composition that varies within a specific limited range. For example: the mineral halite has a chemical composition of Na. Cl. It is made up of an equal number of atoms of sodium and chlorine.

• "Ordered internal structure" means that the atoms in a mineral are arranged in a systematic and repeating pattern. Halite is composed of an equal ratio of sodium and chlorine atoms arranged in a cubic pattern.

• Crystals are solid, geometric forms of minerals produced by a repeating pattern of atoms. • All minerals are grouped into classes according to the kinds of crystal the form.

Types of Minerals • Minerals are divided into two groups based on the elements they are composed of. The two groups are Silicates and Non-Silicates.

Mica Silicates • Silicates contain the two most common elements in the Earth’s crust, silicon & Feldspar oxygen. • Silicates make up 90% of the Earth’s crust. • Examples are: Feldspar, Mica, & Quartz

Non-Silicates • Non-silicates do not contain both Silicon and Oxygen. • Examples are: calcite, galena, pyrite, gypsum, halite

Value of Minerals • Ore is the term used describe mineral deposits that are large enough to be mined for profit. • Ores vary in value and so do gems. Gems are rare and attractive. • After minerals are mined the land has to be reclaimed or put back to it’s original state. The Hope Diamond Ore mine pit

Mining • Surface mining recovers minerals at or near the surface. Example: Strip Mining or Open Pit Mining • Deep Mining far below Earth’s surface. Deep mining tunnels can be horizontal or vertical, depending on where they are located.