Minerals

ESRT Mineral Chart Click Here Key Concept #1 What is a mineral? naturally occurring inorganic A mineral is a definite chemical composition substance which has a What would be the opposite of this? man-made organic random composition ESRT Mineral Chart Click Here

The reason why minerals have different physical properties is due to Key Concept #2 The reason why minerals have different physical properties is due to their internal arrangement of atoms

An example of two minerals which have Key Concept #2 An example of two minerals which have the same chemical composition but different physical properties is Click Here graphite & diamond

The Main Physical Properties Used to Identify Minerals Key Concept #3 The Main Physical Properties Used to Identify Minerals A. Color 1. a poor indicator a. minerals can be multiple colors b. many minerals are the same color

One Mineral, Many Colors

Different Minerals Same Color

The Main Physical Properties Used to Identify Minerals Key Concept #3 The Main Physical Properties Used to Identify Minerals B. Streak more reliable than color the powder form of a mineral

The Main Physical Properties Used to Identify Minerals Key Concept #3 The Main Physical Properties Used to Identify Minerals C. Luster how light reflects off a mineral a. metallic b. non-metallic -looks like a metal -Leaves a dark (black, grey, green or brown) streak on a white streak plate -looks earthy, waxy, greasy or brilliant -leaves white or no streak on a black streak plate

Key Concept #3 The Main Physical Properties Used to Identify Minerals D. Cleavage -mineral breaks in a predictable pattern because of its arrangement of atoms -At least one distinct flat side when broken

Examples of Cleavage

Examples of Cleavage

Examples of Cleavage

Examples of Cleavage

Examples of Cleavage

Examples of Cleavage

Examples of Cleavage

Key Concept #3 The Main Physical Properties Used to Identify Minerals E. Fracture -the mineral breaks randomly -Irregular sides

Key Concept #3 The Main Physical Properties Used to Identify Minerals F. Hardness 1. resistance to being scratched- something softer than a material cannot scratch the harder material 2. It is NOT the same as breaking! For example: You can break glass easily with steel. However, steel will not scratch glass.

The Main Physical Properties Used to Identify Minerals Key Concept #3 The Main Physical Properties Used to Identify Minerals Hardness MOH’S SCALE OF HARDNESS Hardness Mineral 1 (softest) 6 2 7 3 8 4 9 5 10 (hardest) TALC ORTHOCLASE GYPSUM QUARTZ CALCITE TOPAZ FLUORITE CORUNDUM APATITE DIAMOND

oxygen silicon Key Concept #4 Minerals have a definite chemical composition. The two elements by mass that make up the greatest percentage of the Earth’s crust are oxygen silicon

silicates (SiO4) Key Concept #4 Minerals have a definite chemical composition. These two elements combine to form compounds called silicates (SiO4)

silicon-oxygen tetrahedra Key Concept #4 Minerals have a definite chemical composition. They combine in a specific structure called a: silicon-oxygen tetrahedra

REVIEW- WHAT IS A MINERAL? A mineral is naturally occurring, inorganic, and crystalline solid having a definite chemical composition Each mineral has its own distinctive crystal structure that can lead to a very accurate ID All minerals are solids that are composed of one or more chemical elements

All minerals are rocks, but not all rocks are minerals nor are they all composed of minerals- the main reason: rocks can be organic like coal Minerals form as the result of inorganic crystallization or by the re-crystallization of atoms in various rock-forming environments

Minerals can be identified by color, streak, luster, hardness, density, cleavage, crystal structure and other characteristics (ex. magnetism, response to hydrochloric acid, etc)