Ch 2 test Flashcards
The repeating pattern of a minerals’s particles form this solid,
Crystal
This substance must have all 5 characteristics: naturally occurring, inorganic, solid, crystal structure, and definite chemical composition.
Mineral
A mineral must be this?
Inorganic
The color of a minerals powder.
Streak
The term used to describe how light is reflected from a minerals surface.
Luster
A scale that ranks ten minerals from softest to hardest.
MOHs hardness scale
A mineral that splits easily along flat surfaces has this property.
Cleavage
Describes how a mineral looks when it breaks apart in an irregular way.
Fracture
Is generally a light colored rock that has silica content.
Granite
A dark colored rock
Basalt
What do geologist observe when studying a rock sample?
Mineral composition, color, and texture.
How many minerals make up most of the earth’s crust?
About 20
This gives the rock it’s texture.
Grains
The look and fill of a rocks surface.
Texture
Often the grains in a rock are large and easy to see.
Grain size
The grains in a rock vary widely in shape.
Grain shape
The grains in a rock often form patterns.
Grain pattern
Rocks are classified into three major groups.
Igneous rock, sedimentary rock, and metamorphic rock.
Forms from the cooling if magma or lava.
Igneous rock
Forms when particles of other rocks or the remains of plants and animals are pressed and cemented together.
Sedimentary rock
Forms when an existing rock is changed by heat, pressure, or chemical reactions.
Metamorphic rock
Classified according to their origin, texture, and mineral competition.
Igneous rock
Igneous rock formed from lava that erupted onto the earth’s surface.
Extrusive rock
Igneous rock formed when magma hardens beneath the earth’s surface.
Intrusive rock
