Guided Notes about Mineral Formation Chapter 4, Section 1

Define Mineral: A mineral is a naturally occurring, inorganic solid with a specific chemical composition and a crystalline structure

All minerals are naturally occurring, which means that they are formed by natural processes.

All minerals are inorganic, which means that they are not alive, never were alive, and are not made from a living thing.

The 3 rd characteristic of all minerals is that they are solids. They have definite shapes and volumes. No gas or liquid can be considered minerals.

Each type of mineral has a chemical composition unique to that mineral. Some minerals, such as copper, are composed of one element, but the vast majority are made from compounds.

The atoms in minerals are arranged in regular geometric patterns that are repeated again and again.

Define crystal: A crystal is a solid in which the atoms are arranged in repeating patterns

Minerals can form from the cooling of magma, which is the molten material found beneath the Earth’s surface.

As magma cools, the compounds no longer move freely and they may interact chemically to form minerals.

The type and amounts of elements present in magma determine which minerals will form. The rate of cooling determines the size of the mineral crystals. If magma cools slowly, it will form large crystals.

In nature, if a solution becomes super-saturated, or overfilled, with another substance, then mineral crystals will precipitate, or drop out of solution.

Also, when liquid evaporates from a solution, elements remain behind and arrange into crystals.

Of the 3000 minerals found in the earth’s crust, only 30 are common. They are referred to as rock- forming minerals because they make up most of the rocks found in the earth’s crust.

Minerals that contain silicon, oxygen and one or more other elements are silicates. They make up 96 percent of the minerals found in the earth’s crust.

The most common minerals are feldspar and quartz, which are silicates.

Oxygen combines easily with other elements and forms other mineral groups, such as carbonates and oxides.

Carbonates are minerals composed of one or more metallic elements with CO 3. Examples of carbonates are calcite and dolomite. They are the primary minerals found in rocks such as limestone and marble.

Oxides are compounds of oxygen and a metal. 2 common iron oxides are hematite and magnetite.

Fill in the chart below about the major minerals GroupDefinitionExample SilicatesSilicon+oxygen+elementOlivine CarbonatesMetallic element+ CO 3 Calcite OxidesMetal + oxygenHematite SulfidesSulfur + another elementPyrite HalidesCl or F + Ca, Na, or KHalite Native Elements One element only, usually a metallic element copper