1. Mineral Properties

2. Key Concepts
A pure substance, such as a mineral, can be identified from observations and tests performed to determine its physical properties. These properties are based on the unique structure of the substance.
Minerals are crystals that form naturally in the Earth. They have characteristic properties, such as color, hardness, and a crystalline shape.
Rocks are made of minerals.

3. Vocabulary
Crystalline structure – the regular pattern of atoms, molecules or ions in a crystal.
Geologist – scientist who studies the Earth and the changes that take place on and beneath the surface

4. Vocabulary
Mineral – a naturally occurring solid material that has a specific chemical composition and crystal form and characteristic physical properties. There are about 3,500 different minerals.
Rock – a naturally occurring solid substance composed of one or more minerals.

5. Minerals/4 Characteristics
Forms in nature
Is a solid
Has a definite chemical make-up
Has a crystal structure

6. Minerals Form In Nature
Formed by natural processes.
Are inorganic which means they are made of non-living materials found naturally on earth.

7. A mineral has a definite volume and a rigid shape.
Minerals are Solids
A mineral has a definite volume and a rigid shape.
Volume refers to the amount of space an object takes up

8. Definite Chemical Make-up
Every mineral consists of a specific combination of atoms of certain elements.
The types of atoms that make up a mineral are part of what makes the mineral unique.
The way in which the atoms are bonded, or joined together, is also important.
Many properties of minerals are related to how strong or weak the bonds are.

9. Crystal Structure
The way the atoms are arranged in an orderly, repeating three-dimensional pattern.
Each mineral has its own type of crystal structure.
Minerals can have the same chemical compound/same type of atoms, but the way the atoms are arranged is different.
Diamonds and graphite are made of the same element, carbon, but the arrangement of these carbon atoms is different.

10. Mineral Properties
Minerals have characteristic properties that are used to identify them:
1. color Fracture
2. luster Density
3. transparency crystalline structure
4. streak color 8. crystal habit (shape)

11. Look at the following minerals
Look at the following minerals. Which do you think are the same types of minerals and which do you think are different?

12. Haha! Tricked you! These are all…
…the same type of mineral! They are examples of quartz!!

13. Why Is It So Difficult to Identify Minerals?
There are over 3000 types of minerals in the Earth’s crust
As you could see with the quartz, often times even the same kind of minerals can look very different
Therefore, geologists (scientists who study minerals and rocks) often use several different tests to determine type of a mineral they have found!

14. Color
Color is obviously one of the most noticeable characteristics of a mineral, but it also the least reliable of all the characteristics
The color of a mineral is often caused by tiny amounts of other elements or compounds inside
For example, what people call amethyst is actually just quartz with iron in it!

15. Luster
The way that a mineral reflects light from its surface is its luster
The two types of luster are: - metallic - nonmetallic
Metallic Luster

16. Texture Texture describes how a mineral feels to the touch.
Minerals can range anywhere between glassy feeling, rough feeling, greasy feeling, and even soapy feeling!
Talc has a soapy texture.
Fluorite has a glassy texture.

17. Streak
When a mineral is rubbed against a tile, it will leave behind a colored powdered streak on the tile
Sometimes a mineral’s streak does not match the mineral’s external color
For example, one way to tell the difference between pyrite (Fool’s gold) and real gold is by streak. Pyrite leaves a greenish-black streak while real gold leaves a yellow streak.

18. Hardness is a measure of how easily a mineral can be scratched
Associations and Uses 1
Talc
Talcum powder. 2
Gypsum
Plaster of paris. Gypsum is formed when seawater evaporates from the Earth’s surface. 3
Calcite
Limestone and most shells contain calcite. 4
Fluorite
Fluorine in fluorite prevents tooth decay. 5
Apatite
When you are hungry you have a big "appetite". 6
Orthoclase
Orthoclase is a feldspar, and in German, "feld" means "field". 7
Quartz 8
Topaz
The November birthstone. Emerald and aquamarine are varieties of beryl with a hardness of 8. 9
Corundum
Sapphire and ruby are varieties of corundum. Twice as hard as topaz. 10
Diamond
Used in jewelry and cutting tools. Four times as hard as corundum.
Hardness is a measure of how easily a mineral can be scratched
Geologists use Mohs scale to give minerals their hardness ratings

19. Cleavage and Fracture
The pattern of atoms will determine how a mineral will break
A mineral that breaks relatively easily and evenly at angles is said to have cleavage
Minerals that break with rough or jagged edges are said to have fracture

20. Some Other Special Properties
Some minerals have unique properties
For example, Iceland spar can create double images
Some minerals react with hydrochloric acid and release carbon dioxide (bubbles)