1) Occurs naturally (not man-made)2) is a solid3) is a chemical compound arranged in an

orderly pattern (crystals)4) is inorganic (not made from dead plants or

animals)5) Is an element or a compound (unique

chemical formula)

What are Minerals?

• Minerals are grouped by the elements they are made of

Mineral Groups

Amethyst

Beryl (Emerald)

Calcite

Mineral Group Characteristics Examples

Silicates

Contain oxygen & silica The most abundant group of minerals

Quartz, mica

MICA Quartz

Mineral Group Characteristics Examples

Non-Silicates(contain oxygen but not silicon)

Make up only 5% of the Earth’s crust Include some of the most important minerals

iron, copper, gold, silver, diamonds, rubies

Silver

Gold RubyIron

Copper

Diamond

Mineral Group Characteristics Examples

Carbonates Carbon & oxygen and a positive ion, such as calcium

Calcite (CaCO3)

Calcite with Duftite inclusions

Mineral Group Characteristics Examples

Oxides Metallic ion and oxygen

Hematite (Fe2)O3

Mineral Group Characteristics Examples

Sulfides Sulfur and a metallic ion

Galena (PbS)Pyrite (FeS2)

Mineral Group Characteristics Examples

Sulfates Metallic ion, Sulfur & oxygen

Barite (BaSO4)

Barite on Calcite BaSo4 / CaCO3

BariteBaSo4

• 1) Cooling of magma (hot, liquid rock and minerals inside the earth (from the mantle))– Fast Cooling = No Crystals (mineraloids)–Medium Cooling = SMALL crystals– Slow Cooling = LARGE crystals

How Do Minerals Form?

• 2) Elements dissolved in liquids (usually water) will reform into crystals as the water evaporates and the dissolved elements recrystalize.

How Do Minerals Form?

Physical Properties of Minerals (can be used to identify the mineral)

Color• Can be misleading• Can vary with the type of impurities

Physical Properties of Minerals (can be used to identify the mineral)

Streak• The color of the

powdered form of the mineral

• The color of the streak can be different than the mineral

• Minerals must be softer than the streak plate

Streak…can help identify quartz

http://www.childrensmuseum.org/geomysteries/cube/b3.html

Physical Properties of Minerals (can be used to identify the mineral)

Luster• Surface

reflection • metallic = shiny

like metal• non-metallic =

dull, non-shiny surface

Pyrite has a metallic luster

Calcite has a non-metallic luster

Metallic Luster

Nonmetallic Luster

Physical Properties of Minerals (can be used to identify the mineral)

Hardness• How easily a mineral

scratches materials• Mohs Hardness Scale

• Scale from 1 (softest) to 10 (hardest)• Test by seeing if the mineral can

scratch different objects (like human fingernail, copper, penny, glass, steel file)

Breaking Properties:Cleavage or Fracture

• Cleavage – mineral breaks along a flat surface or into sheets

• Fracture – when a mineral breaks with lots of jagged edges

Cleavage or Fracture?1.

2.

4.

Extra Special Properties

1. Fluorescence– Fluorescent color under ultraviolet (UV) light

2. Magnetic– Attract magnets

3. Acid reaction– Carbon dioxide gas bubbles off when you drop

acid on them– Carbonates!

Fluorescence

Magnetic

Carbonate Acid Reaction