1. Chapter Minerals

2. What is a Mineral?
To classify a solid as a mineral, it must have these 5 characteristics:
Must be made in nature
Must be inorganic (cannot contain anything that was alive)
Must have a definite shape and volume
Must have a crystalline structure
Must have a definite chemical composition (made of elements joined in a compound)

3. Rocks are NOT minerals! Rocks can be organic.
Rocks are mixtures, not compounds.
Rocks have no definite composition.
Rocks cannot be grouped by properties.
Rocks are grouped by how they are formed.

4. How to Identify Minerals
Identify minerals by the physical properties
Physical Properties include:
Hardness - Color
Streak Color - Luster
Density - Crystal Structure
Breakage - Fluorescence

5. Physical Prop: Hardness
Use Moh’s Hardness Scale to determine a mineral’s resistance to scratching.
This is a scale with a 1 being softest and a 10 being hardest.

8. Physical Prop: Color Streak: Color of a mineral in powder form
Rub mineral along a streak plate
Luster: how a mineral reflects light.
Metallic, non-metallic, dull, pearly, etc.

9. Streak Test Samples

10. Luster Samples

11. Physical Prop: Density
Found by dividing the MASS of the mineral by the VOLUME
VOLUME is found by measuring the amount of WATER the mineral DISPLACES when put in a container full of WATER

12. Physical Prop: Crystalline Structure
As minerals form, they build atom by atom.
As these atoms stack on top of one another, they tend to follow a certain pattern.
This pattern forms the crystal

13. 6 Crystal Structures (p612)
Cubic (square)
Tetragonal (tall square)
Hexagonal (flat top & bottom, 6 sides)
Orthorhombic (rectangle)
Monoclinic (shifted rectangle)
Triclinic (shifted rectangle on 2 sides)

14. What are these crystal shapes?

15. Physical Prop: How Minerals Break
Fracture: uneven breakage
Cleavage: breakage on an even plane; creates a flat, smooth edge

16. Physical Prop: Florescence
Florescence: Some minerals glow under black light

17. How do Minerals Form?
Magma
Hot Water Solutions
Evaporation

18. Minerals from Magma
When magma cools deep below the surface, it may take months or even years to cool, forming crystals.
Slow cooling leads to the formation of large crystals
Magma closer to the surface cools more quickly leading to smaller crystals

19. Minerals from Water Solutions
Solution of water and materials seep through cracks in the ocean floor
As they reach the heat of the magma underground they crystallize
These crystals are then carried to the surface in an eruption depositing the crystals on the volcano’s surface
Include: silver veins, gold veins, copper veins

20. Minerals from Evaporation
Crystals form when a solution evaporates leaving behind the crystallized mineral.
Including:
Gypsum – used in drywall
Calcite – used in microscopes
Potassium – used in fertilizer

21. Largest Mineral Group
There are many mineral groups but the most abundant on Earth are the silicates.
Silicates contain silica or SiO2
Silicates will always contain Si, O, and possibly other elements
Quartz and feldspar, common silicates, make up most of Earth’s crust.

22. Uses of Minerals
Metals like copper and iron can be used for wiring or building purposes.
Ore: rocks contain metal & useful minerals
Vein: narrow mineral channel underground
Other useful minerals are:
Quartz - used in watches
Corundum - used in polishes and cleaning products
Gypsum – drywall
Gemstones (diamond, ruby, etc) - beauty

23. Chapter 20.2: Igneous Rocks

24. What is a rock?
A rock is a mixture of minerals, rock fragments, volcanic glass, possible organic life forms.
Rocks can be identified by texture (how they feel or look) and composition (what minerals they may contain).
Texture can indicate how a rock formed.

25. Texture Coarse grained: very visible crystals
Fine grained: not visible crystals
Porphyritic: has both large and tiny crystals
Vesicular: large gas pockets form
Silica rich magmas produce rocks that are colorful and speckled
Basaltic rich magmas produce uniform colors (high in iron and magnesium)

26. Igneous Rocks Igneous rocks: cooling of magma or lava.
There are two types of igneous rocks:
Intrusive
Extrusive

27. Intrusive vs. Extrusive
Intrusive: from magma deep under the crust.
Large grain size from slow cooling
Non-uniform texture
Examples: Granite, gabbro

28. Intrusive vs. Extrusive
Extrusive: formed from lava cooling on surface
Microscopic or NO grains are visible (due to cooling quickly)
Uniform texture
Examples: Basalt, pumice

29. Chapter 20.3
Sedimentary Rock

30. How is Sedimentary Rock Formed?
Sediment- small pieces of material that come from rocks or living things

31. How Sedimentary Rock is Formed
Erosion- water, grinding ice, wind, waves or gravity move fragments of rock and soil
Deposition- sediments settle out of the water or wind that is carrying it and are deposited in a new location

32. How Sedimentary Rock is Formed
Compaction- sediments are pressed together under their own weight
Cementation- dissolved minerals crystallize and glue particles of sediment together into one mass

33. Three Types of Sedimentary Rock
Detrital (Clastic): form when rock fragments are squeezed together; based on clast size
Shale: tiny fragments
Sandstone: made of sand sized particles
Conglomerate – made of large particles with rounded edges
Breccia – made of large particles with jagged edges

34. Three Types of Sedimentary Rock
Chemical rocks: form by evaporation of water that contains minerals
Examples: Limestone, halite (rock salt). These pics. are from the halite deposit under Detroit!

35. Three Types of Sedimentary Rock
Biochemical: rocks that contain the remains of living things and minerals
Examples: coral, fossils, coal, some limestone

36. Metamorphic Rock and the Rock Cycle
Chapter 20.4
Metamorphic Rock and
the Rock Cycle

37. What is Metamorphic Rock?
Metamorphic rock: formed from heat and pressure (and chemical activity)
These rocks tend to form deep underground near the upper mantle.
Two ways to classify metamorphic rock:
Foliated
Non-foliated

38. Foliated vs. Non-foliated
Foliated rocks- Metamorphic rocks that have bands or layers
Non-foliated rocks- Metamorphic rocks that do not have bands or layers

39. Types of Metamorphic Rock
Granite (I) becomes Gneiss
Shale (s) becomes Slate
Sandstone (s) becomes Quartzite

40. Uses of Metamorphic Rock
Marble
Comes from limestone that has undergone metamorphosis
Used in building
Slate
Comes from shale that has undergone metamorphosis
Used in roofing, flooring, and chalkboards

41. The Rock Cycle
This large diagram shows that ALL rock types can turn into other rock types!

44. Ch 20 Mineral Analysis: Date__ Name________________ Hr__
Copy and answer in complete sentences
Are lab diamonds considered minerals?
A&B) Describe 2 ways minerals form.
Compare mineral fracture and cleavage.
Why should you test more than 1 physical property when identifying minerals?