where do minerals form?
TRANSCRIPT
Where Do Minerals Form?
Minerals to Know: (formation and identifiable characteristics)
QuartzHalitePyriteMica
◼ Quartz and Mica
◼ Quartz –white/colorless streak
◼ Mica – forms in 3 ways
◼ Magma cools as it moves toward the crust forming small crystals - Plutons
Mica
Quartz
◼ Halite
◼ Cubic crystal
◼ Tastes like Salt
◼ NaCl
◼ Evaporation:
◼ Water evaporates and leaves mineral crystals
Halite
◼ Pyrite
◼ Fool’s Gold
◼ Black Steak
◼ Composed of Leadand Sulfur
◼ Ground water sinks into the mantle; mixes with minerals and forms a metal crystal
Pyrite
◼ Magma/Inside the Earth
◼ Extreme heat and pressure change an existing mineral into a new one –Metamorphic Mineral
Mica
How Are Minerals Identified?
◼ Color
◼ Luster
◼ Hardness
◼ Streak
◼ Cleavage and Fracture
◼ Special Properties
Color◼ Usually the first and most easily observed
◼ The color minerals appear in normal light
-Some minerals are always the same color
-Some minerals can have many colors
QUARTZROSE QUARTZ SMOKY QUARTZ
Moh’s Mineral Hardness Scale
1) Talc
2) Gypsum
3) Calcite
4) Flourite
5) Apatite
6) Feldspar
7) Quartz
8) Topaz
9) Corundum
10) Diamond
Softest
Hardest
1
2
3
4
5
6
7
8
9
10
Streak
◼ The color of the minerals fine powder
◼ Determined by rubbing the mineral on a piece of unglazed porcelain (streak plate)
Cleavage & Fracture◼ The tendency of a mineral to split or crack along flat edges
◼ Cleavage—minerals break along smooth, flat surfaces and every fragment has the same general shape
◼ Fracture—minerals that break at random with rough or jagged edges
Cleavage or Fracture?
1.4.
3.2.
Physical Properties of Minerals(can be used to identify the mineral)
Other Properties (Only Unique to certain minerals)◼ Attraction to magnets
◼ Fluorescence
◼ Reaction with hydrochloric acid
◼ Smell & taste
Know these rocks
◼ Igneous: Scoria and Obsidian
◼ Sedimentary: Shale and Coquina limestone
◼ Metamorphic: Marble, Quartzite, and Schist
Rocks
▪ Naturally Occurring
▪ Solid
▪ Made of two or more different minerals that have been:
◼cemented together
◼squeezed and heated together
◼melted and cooled together.
Igneous Rocks
◼ Igneous rocks are produced by the cooling and hardening of magma and lava.
◼ Origin:
◼ Intrusive
◼ Extrusive
◼ Texture:
◼ Coarse-grain
◼ Fine-grain
◼ No grain
◼ Composition:
◼ Felsic – light colors; High silica (sand)
◼ Mafic – dark colors; Low silica (sand)
Composition
◼ Extrusive- Formed from lava; volcanic
◼ Intrusive- Formed from magma deep within the earth
Obsidian Pumice
Granite
Scoria
Sedimentary Rocks◼ Formed from the breaking apart of other rocks (igneous,
metamorphic, or sedimentary rocks)
◼ Steps to Formation
◼ Erosion
◼ Deposition
◼ Compaction
◼ Cementation
◼ Composition
◼ Clastic
◼ Chemical
◼ Organic
Classification of Sedimentary Rocks
◼ Clastic Rocks- Made of the fragments of previously existing rocks
◼ Organic Rocks- Come from organisms
◼ Chemical Rocks- Formed by inorganic processes such as evaporation
Metamorphic Rocks
◼ Formed from heat and pressure changing an existing into a completely new rock.
◼ Parent Rock
◼ Igneous, Sedimentary, Metamorphic
◼ Texture:
◼ Foliated
◼ Unfoliated/Nonfoliated
Metamorphic Rocks
◼ Foliated- Parallel alignment of flattened mineral grains and pebbles
◼ Unfoliated-Rocks that are not banded and do not break into layers
Foliated
Gneiss
Parent - GraniteSlate
Parent –Shale/Mudstone
SchistParent – SlateGrandparent –Shale/Mudstone