1. Minerals
Chapter 3 Lesson 1
p.142

2. Before we get started…
There are a few things we need to know before we get into minerals
element- a pure substance that cannot be broken down into simpler substances by ordinary chemical means
Atom- smallest unit of an element that maintains the properties of that element
Molecule- stable particles made up of strongly bonded atoms
Compounds- molecules of 2 or more elements

3. What is a mineral?
Mineral- a naturally occurring, usually inorganic solid that has a definite crystalline structure & chemical composition

4. What Do Minerals Have in Common?
Definite Chemical Composition
Solid
Usually Inorganic
Crystalline Structure
Naturally Occurring

5. Definite Chemical Composition
Determined by the element or compound that makes up the mineral
Native Element: minerals composed of only 1 element
Ex: Gold or Silver
Quartz is a compound where silicon atoms have bonded with oxygen atoms in a repeating pattern

6. Solid
State of Matter
Matter- anything that takes up space; has volume and mass
Volume: amount of space that is taken up
Mass: the amount of matter in an object
Weight: Gravitational pull on an object
Solids –Liquids – Gases
What is ice?

7. Usually Inorganic
Is not made up of living things or the remains of living things.
Most minerals are inorganic

8. Crystalline Structure
Minerals have a crystalline structure because they have crystals
Crystal- solid, geometric form that results from a separating pattern of atoms or molecules.
Crystal shape is produced by the arrangement of atoms or molecules & the conditions under which it forms
Can be placed into crystal classes based on their shape

9. Naturally Occurring Minerals formed from natural processes Examples:
Water Evaporating
Water Cooling
Rock Cooling
High Temperature & Pressure

10. How Are Minerals Formed?
Minerals form within Earth or on Earth’s surface
As Magma & Lava are cooled
By Metamorphism
From Solution

11. Cooling Magma / Lava Many minerals come from magma
As magma cools, atoms join together to form minerals
Same applies to lava
Example: Quartz

12. Metamorphism
Temperature & pressure cause new minerals to form as bonds break and atoms create new bonds with different atoms
Ex: Diamonds, Graphite

13. Solutions
When water evaporates, substances in water are left behind & form solids
Ex: Gypsum
Hot water is able to dissolve more materials than cold water
As hot water cools, substances can form solids that precipate out of a solution
Ex: Dolomite

14. How Are minerals Classified?
Most common mineral classification is based on chemical composition
Silicates
Nonsilicates

15. Silicate Minerals
Minerals that contain a combination of silicon and oxygen
Silicon & oxygen are 2 of the most common elements found in Earth’s crust
Obviously Silcate minerals make up most of Earth’s crust.
Examples: Quartz, Feldspar (silicate tetrahedron)
Examples: Mica, Olivine (silicate tetrahedron combined w/ other elements)

16. Nonsilicate Minerals
Elements that do not contain a silicate tetrahedron
These minerals can be made up elements such as sulfur, carbon, iron, fluorine, & even oxygen
A nonsilcate mineral’s chemical composition determines its class.

17. What Properties Can Be Used To ID Minerals?
Color
Streak
Luster
Cleavage or Fracture
Density
Hardness
Special Properties

18. Color The same minerals can have different colors Vice Versa
So color is a good start to identification, but not enough on its own

19. Streak Streak- The color of the powdered form of a mineral
Found by rubbing a mineral against a white tile
Called a streak plate
Not always the same color as the mineral
Streak is not affected by water or air
More reliable than color for ID’ing a mineral

20. Luster Luster- the way surface reflects light Metallic Nonmetallic
Silky
Pearly
Earthy
Waxy
Shiny
Resinous
Glassy

21. Cleavage or Fracture
Cleavage- tendency of a mineral to split along specific planes of weakness to form smooth, flat surfaces
Flake like breaks
Many minerals do not break along these weaknesses
Some fracture or break unevenly
Uneven breaking is called a fracture

22. Hardness A mineral’s resistance to being scratched
Mohs Hardness scale used to measure hardness
The greater the mineral’s resistance to being scratched – the greater its hardness rating
If the reference mineral scratches your mineral , the reference mineral is as hard or harder than your mineral

23. Density
Is the measure of how much matter is in a given amount of space.
Measure in grams per cubic centimeter
g/cm3
Gold can be ID’ed from pyrite this way

24. Special Properties
All minerals exhibit the 6 properties we just went over
Some minerals have extra properties such as:
Magnetism
Double Image
Ultraviolet