Minerals and Mineral Identification First Lesson in geology

What is a Mineral? Mineral: A naturally occurring, inorganic solid substance that has a definite chemical composition and crystalline structure. 1. This means that it is NOT manmade, that it DOES NOT come from something living or once living, and what it is made up of is known.

What Gives Minerals Their Physical Properties? 2. The internal arrangement of atoms gives minerals their different physical properties These properties include things like: hardness, breakage pattern and streak Ex. of minerals with same composition but different physical properties: graphite and diamond Graphite = pencil lead Diamond= hardest mineral, valuable!

B. Properties Used to Identify Minerals Color It is difficult to tell what a mineral is based on color because minerals can be multiple colors and many minerals are the same color.

One Mineral, Many Colors

Different Minerals Same Color

more reliable than color the powder form of a mineral 2. Streak more reliable than color the powder form of a mineral

how light reflects off a mineral a. metallic b. non-metallic 3. 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 -usually looks glassy or dull -leaves white or no streak on a black streak plate

4. Cleavage -mineral breaks in a predictable pattern because of its arrangement of atoms -At least one distinct flat side when broken

Examples of Cleavage

-the mineral breaks randomly 5. Fracture -the mineral breaks randomly -Irregular sides

6. Hardness 1. resistance to being scratched- a softer material cannot scratch a 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.

Do not write: Hardness TALC GYPSUM QUARTZ CALCITE TOPAZ FLUORITE 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

Video Watch the following video and write down 3 notes about it in your notes. If the link does not work, search for “Geology Kitchen What is a Mineral” in YouTube. Watch “What is a Mineral” and “Properties of Minerals” https://www.youtube.com/watch?v=rTXSwnkieZc https://www.youtube.com/watch?v=cjA2-MrWAVU