Minerals

What is a mineral? A mineral occurs naturally, it’s inorganic, a solid that has crystal structure and definite chemical composition.

Inorganic, Solid, Crystal Structure and Definite Chemical Composition Inorganic: a mineral cannot come from another living thing. Solid: all minerals have definite shape and volume. Crystal Structure: The particles of a mineral line up in a pattern that repeats itself. The repeating pattern forms crystals. Definite Chemical Composition: The mineral always contains certain elements in definite proportions. Almost all minerals are compounds, For example the mineral quartz has one atom of silicon and 2 atoms of oxygen. and 2 atoms of oxygen. Some elements occur in a pure form and not as a compound. Elements such as copper, silver and gold are all minerals. Almost all pure, solid elements are metals.

Identify Minerals Each kind of mineral has certain properties that you can use to identify it. Hardness is the ability of a mineral to resist being scratched. A harder mineral will always scratch a softer one. German scientist Friedrich Mohs developed a system for comparing hardness of a mineral to 10 common minerals.

Properties that Identify Minerals Color-A mineral may be on color or many colors. You cannot identify a mineral by color alone. Luster- This property describes how a mineral reflects light from its surface.Some minerals are shiny like metal or glass. Others have dull, waxy or earthy luster. Streak- The streak of a mineral is the color of its powder. You can find out mineral’s streak by rubbing it across an unglazed porcelain streak plate. The color may differ from the color of the mineral. Density-Each mineral has a characteristic density. Density is the mass in a volume. D=M/V

Properties that Identify Minerals Crystal Shape- The atoms of a mineral are arranged in a certain pattern. That pattern may result in a distinct crystal shape for the mineral. The pattern of the atom affects its cleavage. Cleavage and Fracture- Minerals break according to how their atoms are arranged. Cleavage is the tendency of a mineral to break along a flat surface where layers of atoms are attached weakly to each other. Fracture is the tendency of a mineral to break in a way that is not along a flat surface. Special Properties- Some minerals can be identified by special physical properties. Example: magnetism, radioactive, reaction to acids and fluorescene.

How Minerals Form Minerals can form from Magma and Lava Minerals form from solutions.

Minerals from Magma and Lava Mineral forms as hot magma cools inside the crust or as lava hardens on the surface. When these liquids cool to a solid state they form crystals.

Minerals from a solution Solution is a mixture in which one substance is dissolved in another. When elements and compounds that are dissolved in water leave a solution, crystallization occurs. Minerals can from in this way underground and in bodies of water on Earth’s surface. Minerals form when solutions evaporate. Minerals from hot water solutions- deep underground magma can heat water to a high temperatures. Sometimes the elements and compounds that form minerals dissolve in this hot water. When the water solution starts to cool,the elements leave the solutions and crystallize as minerals.

Using Mineral Resources Minerals are the source of gemstones, metals and a variety of materials used to make many products.