Earth's Minerals

Mineral

A mineral is a naturally occurring, inorganic solid with a definite chemical composition and an orderly arrangement of atoms or ions.

Naturally Occurring

There are about 4,000 minerals in the world. Ten of these are called the rock-forming minerals. These minerals occur naturally and are not made in the lab.

How do minerals form

They form through the process of crystallization. Minerals can crystallize from either hot or cool solutions for example, the mineral halite forms from cool solutions. Where water with dissolved solids leaves the halite crystals behind.

Magma

is a molten rock stored beneath earth's surface. When molten rock erupts on or near earth, its called lava or ash.

Crystallization

The process occurs when particles dissolved in a liquid or a melt solidly and form crystals.

Solid

A solid is matter with tightly packed atoms or ions. To be a mineral a solid must have a crystal form.

Minerals from Magma

As lava or ash cools above ground or magma cools underground, atoms and ions arrange themselves and form mineral crystals.

Common Minerals

Common-rock forming minerals are composed of combinations of elements that are abundant in earth's crust. The two most abundant elements in the crust are oxygen and silicon. Feldspar is the most common silicate mineral in the Earth's crust.

Silicate

Is a member of the mineral group that has silicon and oxygen in its crystal structure.

Inorganic

Minerals form in different environments due to evaporation and crystallization. This variety of gypsum is called desert rose die to its rose petal like appearance. During being inorganic some minerals can form as a result of organic processes for example marine organisms can extract dissolved solid from seawater and make their shells

Definite Chemical Composition

Minerals have a definite chemical composition. Any material made of two parts iron and three parts oxygen is called hematite. some minerals such as silver and sulfur are composed of just one element. These are called native elements.

The Structure of Minerals

Recall that minerals have definite crystalline form and that the shape reflects the internal arrangement of atoms or ions.e Well formed quartz crystals are long and typically have distinctly pointed ends. Well formed calcite crystals are somewhat diamond shaped and have sets of parallel sides.

Changes in Minerals

Some minerals form very far done in the earth. these minerals are stable under high pressure and high temps. Metamorphic activity can uplift minerals from great depths onto earth's surface. Because pressure on earths surface is a lot lower the minerals become unstable. Changes in temp and pressure with agents of erosion can break them down then new rocks form.

Crystalline Form

The internal arrangement of atoms or ions determines the shape of a crystal. A repeating arrangement of atoms or ions in three directions makes it a crystal

Minerals from hot solutions

Water on Earth's surface can flow through cracks in the crust into deep and hot environments. These hot solutions sometimes carry with them large concentrations of dissolved solids. When conditions were just right gold crystallized from the hot-water solution and filled the hole in the rocks.

Crystal Shape

When a crystal has the right conditions and the time too grow, it will develop a characteristic crystal shape. Most minerals grow in clusters. Scientists can examine them by scanning electron microscope images.

Minerals from Cool Solutions

When it rains or snow melts and the water moves, it interacts with minerals on rocks and the soil. The water dissolves and picks up some elements such as potassium, calcium, iron, and silicon.