1. What Are Minerals?
Minerals – a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition

2. What 5 Characteristics Does a Mineral Have to Have?
A mineral must be:
Naturally Occurring
Inorganic
Solid
Crystal Structure
Definite Chemical Composition

3. What Does It Mean to Be Naturally Occurring?
A mineral must occur naturally
Cement, brick, steel, and glass all come from substances found in Earth’s crust but they are manufactured by people

4. How Can Something Be Inorganic?
Inorganic – the mineral cannot arise from materials that were once part of a living thing
Ex. Coal is NOT a mineral because it is made up the remains of plants and animals

5. What kind of pattern must a mineral have?
A mineral must have a crystal structure – a repeating pattern of a mineral’s particles that forms a solid.
Faces – a crystal’s flat side that meets at sharp edges and corners

6. What kind of composition must a mineral have?
A mineral must have a definite chemical composition – it always contains certain elements in definite proportions; most minerals are compounds
Cinnabar – composed of the elements Mercury and Sulfur

7. What Is the Difference Between an Element and a Compound?
Element – a substance composed of a single kind of atom. Ex. Hydrogen
Compound – Two or more elements combined so that the elements no longer have distinct properties Ex. Water H20

8. What are the 2 groups of minerals?
All minerals can be divided into Silicates and Non-silicates
Silicates= Si and O are the two most abundant elements in the earth’s crust.

9. SiO4: One Silicon, Four Oxygen

10. What are the Non-Silicates?
4% of the Earth’s Crust
Carbonates, Halides, native elements.

11. Oxides>>> sulfates>> sulfides>>
Slide 10 cont’d more non-silicates
Oxides>>>
sulfates>>
sulfides>>

12. How Do You Identify Minerals?
Properties:
Density
Crystal Shape
Cleavage and Fracture
Special Properties
Hardness
Color (this can vary)
Streak
Luster

13. How Do You Determine a Mineral’s Hardness?
Friedrich Mohs invented a test to describe and compare the hardness of minerals
Mohs Hardness Scale
Ranks ten minerals from softest to hardest

14. How Does the Mohs Scale Work?
Gypsum (2) will scratch talc (1), calcite (3) will scratch gypsum (2), fluorite (4) will scratch calcite (3), etc.

15. To remember the Mohs scale try remembering this phrase:
The Geologist Can Find An Ordinary Quartz, (that) Tourists Call Diamond!

16. The streak of a mineral is the color of its powder
What Is a Streak Test?
The streak of a mineral is the color of its powder
The streak color and the mineral color are often different
To test: rub a mineral against an unglazed tile (streak plate)

17. What is the Luster of a mineral?
Luster – used to describe how a mineral reflects light from its surface
Minerals containing metals are often shiny
Earthy, waxy, and pearly

18. What does Density have to do with Minerals?
Each mineral has a characteristic Density
Density – or mass per unit volume; Density = mass/volume
Displacement – the volume of the displaced water equals the volume of the the sample

19. What Kind of Shape does a Mineral have?
Minerals have a crystal structure
Cubic
Hexagonal
Tetragonal
Orthorhombic
Monoclinic
Triclinic

20. What is Mineral Cleavage?
Cleavage – A mineral’s ability to split easily along a flat surface
The ability to break apart depends on the arrangement of the atoms in the mineral
Cubic Cleavage
Basal Cleavage

21. What is Mineral Fracture?
Fracture – How a mineral looks when it breaks apart in an irregular way

22. What Special Properties does a Mineral have?
Fluorescence –minerals that glow under ultraviolet light
Magnetism - ex. Loadstone
Chemical Reactivity- ex. Calcite gives off carbon dioxide
Electrical Properties – ex. quartz

23. How are Minerals Formed?
Two General Ways:
Crystallization of melted materials
Minerals from Magma
Crystallization of materials dissolved in water
Minerals from Hot water solutions
Minerals formed by evaporation

24. What is Crystallization?
the process by which atoms are arranged to form a material with a crystal structure

25. How do Minerals form from Magma?
Minerals form as magma cools inside the crust, or as lava hardens on the surface

26. What Effects Crystal Size?
Rate at which magma cools
Slower cooling forms larger crystals
The amount of gas the magma contains
The chemical composition of the magma

27. How do Minerals Form from Hot Water Solutions?
Magma beneath Earth’s surface has heated the water to a high temperature beneath Earth’s surface causing minerals to dissolve
When this solution cools the elements and compounds leave the solution and crystallize as minerals

28. How are Minerals Formed by Evaporation?
As water turns to vapor it leaves behind the mineral
Example: A salt water solution leaves behind large crystals of salt

29. Where are Minerals Found?
Earth’s crust is made up of a variety of minerals however; rare and less common minerals are usually located near plate boundaries because of volcanic activity and mountain building

30. Minerals are the source of Metals ex. Aluminum, Iron
How are Minerals Used?
Minerals are the source of
Metals ex. Aluminum, Iron
Gemstones ex. Rubies and Sapphires
Other Useful materials ex. Talc (talcum powder)

31. Ore - A rock that contains a metal or economically useful mineral
Ore What?
Ore - A rock that contains a metal or economically useful mineral
Most metals, gemstones, and useful minerals must be separated from their ores