What is a Mineral n Naturally occurring inorganic

What is a Mineral? n Naturally occurring, inorganic solid with a crystal structure and definite chemical composition. Pyromorphite

What do all minerals have in common? All: 1. 2. 3. 4. 5. Are formed by natural processes. Are NOT alive and NEVER were alive Have a definite volume and shape Are elements or compounds with a unique chemical makeup (2 or more elements) Are made up of particles that are arranged in a pattern that is repeated over and over (called a CRYSTAL)

How do minerals form? n 1) Cooling of magma (hot, liquid rock and minerals inside the earth (from the mantle)) Fast Cooling = No Crystals (mineraloids) n Medium Cooling = small crystals n Slow Cooling = large crystals n

How do minerals form? n n n 2) Elements dissolved in liquids (usually water) 3) Changes in pressure and temperature 4) formation of hydrothermal solutions -when hot solutions touch existing minerals, chemical reactions take place and form new minerals.

1. What element are diamonds made from? 2. What do all crystals have in common?

Groups of Minerals n Minerals are grouped by the elements they are made of. Beryl (Emerald) Calcite Amethyst

Mineral Group Silicates Characteristics n. Contain oxygen & silica n. The most abundant group of minerals MICA Examples Quartz, mica Quartz

Mineral Group Carbonates Characteristics n. Carbon Examples & Calcite (Ca. CO 3) oxygen and a positive ion, such as calcium Calcite with Duftite inclusions

Mineral Group Oxides Characteristics Metallic ion and oxygen Examples Hematite (Fe 2)O 3

Mineral Group Sulfides Characteristics Sulfur and a metallic ion Examples Galena (Pb. S)

Mineral Group Sulfates Barite on Calcite Ba. So 4 / Ca. CO 3 Characteristics Metallic Examples ion, Barite (Ba. SO 4) Sulfur & oxygen Barite Ba. So 4

Mineral Group Halides Characteristics Halogen ions Examples Flourite (Ca. F 2) Halite (Na. Cl)

Mineral Group Characteristics n. Make up only 5% of the Earth’s crust n. Single elements Native Elements Silver Examples iron, copper, gold, silver, diamonds, rubies Copper Diamond Gold Ruby Iron

QUIZ BREAK

How many mineral groups can you name? Can you tell me some of the examples?

Physical Properties of Minerals (can be used to identify the mineral) Color n Can be misleading n Can vary with the type of impurities

Physical Properties of Minerals (can be used to identify the mineral) Streak n The color of the powdered form of the mineral n The color of the streak can be different than the mineral n Minerals must be softer than the streak plate

Streak…can help identify quartz http: //www. childrensmuseum. org/geomysteries/cube/b 3. html

Physical Properties of Minerals (can be used to identify the mineral) Luster n Surface reflection n metallic = shiny like metal n non-metallic = dull, non-shiny surface Pyrite has a metallic luster Calcite has a non-metallic luster

Physical Properties of Minerals (can be used to identify the mineral) Hardness n How easily a mineral scratches materials n Mohs Hardness Scale from 1 (softest) to 10 (hardest) n Test by seeing if the mineral can scratch different objects (like human fingernail, copper, penny, glass, steel file) n

Find out more… n “Electronic” Hardness Test http: //www. childrensmuseum. org/geomy steries/cube/b 2. html

Physical Properties of Minerals (can be used to identify the mineral) Cleavage & Fracture The way the mineral breaks n Cleavage—minerals break along smooth, flat surfaces and every fragment has the same general shape n Fracture—minerals that break at random with rough or jagged edges n

Crystal form n If space is not restricted, a mineral will exhibit a crystal pattern with a definite number of sides and specific angles.

Cleavage or Fracture? 1. 4. 2. 3.

Physical Properties of Minerals (can be used to identify the mineral) Other Properties Specific gravity (*excellent clue to mineral’s identity) http: //www. childrensmuseum. org/geomysteries/cube/b 4. html n Attraction to magnets n Bending of light n Reaction with hydrochloric acid n Smell & taste n

1. If a mineral can scratch your fingernail, the mineral is ________ than your fingernail. 2. What is luster?