Chapter 2 Test Flashcards
Fracture
Tendency to beak with rough or jagged edges
Cleavage
Tendency to break along smooth flat surfaces
Hardness
The measure of how easily a mineral can be scratched
Luster
Reflection of light from a minerals surface
Streak
Color left by powdered mineral on unglazed porcelain
What three tests can you perform to help you identify an unknown mineral sample?
Hardness,cleavage or fracture test, streak and luster
What are minerals?
A naturally occurring,inorganic, solid substance with a specific composition and crustal structure
Why is color NOT a good property to use to identify a mineral sample?
Many minerals share the same color
Igneous rocks
Form from the cooling and solidification of magma or lava
Where do igneous rocks form?
1) intrusive environment-form below earths surface, slow cooling, large crystals
2) extrusive environment-form on ergs surface, rapid cooling,fine or no crystals
All igneous rocks begin in the______ state of matter
Liquid
Lava
Molten rock at Earths surface
Magma
Molten rock within Earths surface
What three ways that scientists use to classify igneous rocks?
Texture, rate of cooling and origin
Describe how cooling affects the size of mineral grains in an igneous rock
The slower the rate of cooling the bigger the crystals
Sedimentary rocks
Form from the accumulation of sediments on Earths surface
Types of textures of sedimentary rocks
Clastic
Crystalline
Bioclastic
How to determine a sedimentary rock?
Texture and composition
Put the following sediments in SMALLEST TO LARGEST(6)
Clay,silt,sand,pebbles,cobbles and boulders
What are metamorphic rocks made form?
Pre-existing rock
Regional metamorphism
- changed by intense pressure
- deep within the earths crust
- texture foliated
- large geographic area
Contact metamorphism
- the rock is recrystallized by heats of magma and lava
- non foliated
- small geographic area
How to identify metamorphic rocks?
Texture and mineral composition
Explain why metamorphic rocks don’t form on the earths surface
There’s no pressure
Which rock type forms deep below earths surface?
Metamorphic rock
Which rock type forms in bodies of water?
Sedimentary rock
Which rock type forms both on and below the surface of the earth?
Igneous rocks
Dilute hydrochloric acid test is for the mineral________
Calcite
Crystal structure(shape) is a result of an____________
Orderly atomic structure
