Unit 3: Rocks and Minerals
How are the major processes that drive the rock cycle related?
How are physical properties used to determine the mineral being investigated?
Vocabulary
Rocks-- a solid mixture of minerals in any combination
Mineral-- any solid substance found in nature that is made from a set ratio of elements; over 4,000 types; components that make rocks
Summary
Geologists use a variety of tests to distinguish between minerals. Streak is found by rubbing a mineral on an unglazed tile or sand paper. The powder left behind is called streak. Luster is how light reflects from a surface. Some minerals have a vitreous (glassy) luster while others have a metallic or oily luster. How a mineral breaks can be classified as cleavage or fracture. If a mineral breaks naturally breaks with flat surfaces we say it has cleavage. If a mineral had a jagged, rough break, we say it has fracture. A test we can do to determine hardness involves fingernails, glass, and steal. A mineral can only be scratched by something harder than itself. By using the Moh's hardness test, we can determine the approximate hardness of many minerals.
Rocks-- a solid mixture of minerals in any combination
Mineral-- any solid substance found in nature that is made from a set ratio of elements; over 4,000 types; components that make rocks
Summary
Geologists use a variety of tests to distinguish between minerals. Streak is found by rubbing a mineral on an unglazed tile or sand paper. The powder left behind is called streak. Luster is how light reflects from a surface. Some minerals have a vitreous (glassy) luster while others have a metallic or oily luster. How a mineral breaks can be classified as cleavage or fracture. If a mineral breaks naturally breaks with flat surfaces we say it has cleavage. If a mineral had a jagged, rough break, we say it has fracture. A test we can do to determine hardness involves fingernails, glass, and steal. A mineral can only be scratched by something harder than itself. By using the Moh's hardness test, we can determine the approximate hardness of many minerals.