Understanding Minerals: Formation, Identification, and Properties

Minerals WHAT IS A MINERAL? HOW DO MINERALS FORM? HOW CAN MINERALS BE IDENTIFIED?

Key Terms Mineral Lattice Luster Streak Hardness Cleavage Fracture Crystal form Density Inorganic Chemical formula Minerals are the building blocks of rocks, and therefore of the earth itself. To be a Mineral, Something Must. . .

Naturally Occurring Naturally occurring means the substance cannot be human-created. Naturally Occurring Solid For example: Inorganic Ice found in snowflakes or glaciers are minerals Orderly Crystal Grid or Lattice Ice in your kitchen freezer is not made naturally and is not a mineral. Have A Definite Chemical Formula Liquids and gases can become minerals only if they change to a solid.

Solid Always solid state of matter Naturally Occurring Solid Definite volume and shape Particles are packed together very tightly Inorganic Orderly Crystal Grid or Lattice Cannot move compared to a liquid or gas Have A Definite Chemical Formula

Inorganic or Organic Inorganic means carbon that comes from living things is not present. Naturally Occurring Solid Inorganic Minerals are not formed from organic materials such as plant or animal remains. Orderly Crystal Grid or Lattice Have A Definite Chemical Formula

Crystalline Grid or Lattice The atoms in minerals are arranged in an orderly pattern that repeats itself throughout the substance Naturally Occurring Solid Inorganic Orderly Crystal Grid or Lattice This structure, because of the chemical formula, is called crystalline. Have A Definite Chemical Formula

Crystalline Grid a/k/a Lattice Notice the difference in a mineral s orderly and repeating structure when compared to the randomly arranged atom of a non- mineral. Naturally Occurring Solid Inorganic Orderly Crystal Grid or Lattice Have A Definite Chemical Formula

Definite Chemical Formula When the atoms are the same in number and type, the chemical formula is known. Naturally Occurring Solid Inorganic Regardless of the state of matter (solid, liquid, or gas) a specific mineral will have the same formula throughout. Common formulas are: Water: H2O Diamonds: C Orderly Crystal Grid or Lattice Have A Definite Chemical Formula

Minerals Form in Four Ways Crystallization from magma or other liquids Crystalline structure can occur when melted rock material cools into a solid. Precipitation from solution Heat and Pressure Hydrothermal solutions Water will crystalize when a lake freezes over and ice covers its surface.

Minerals Form in Four Ways Crystallization from magma or other liquids Precipitation from solution Minerals dissolved in water (solution) can precipitate (fall to the bottom) when the concentration is high enough. Heat and Pressure Hydrothermal solutions

Minerals Form in Four Ways Crystallization from magma or other liquids Extreme heat and pressure in the Earth can cause minerals to change form without actually melting them. Precipitation from solution Heat and Pressure Because of this, different chemical bonds can form that changes the crystal lattice. Hydrothermal solutions

Minerals Form in Four Ways Crystallization from magma or other liquids Beneath the Earth s surface water is super-heated so that it remains liquid instead of becoming steam. Precipitation from solution Heat and Pressure Hydrothermal solutions When this super-heated chemical solution contacts rocks and other minerals a new mineral is formed as a result other the chemical reaction.

Mineral Identification 1. Color Natural appearance 2. Streak Powdered form 3. Luster Metallic or Non- Metallic

Mineral Identification 4. Hardness Moh s Hardness Scale 5. Crystal System Six structures

Other Methods of Mineral Identification Density Mass per unit of volume (D = Mass/Volume) Cleavage and Fracture how does it break? Special Properties optical or electrical properties