Chapter 4: Minerals Flashcards
How many minerals are in the Earth’s crust
3000
What is a mineral
A naturally occurring, inorganic solid, with a specific chemical composition, and a definite crystalline structure
Why is salt a mineral, but sugar is not?
Salt is a mineral because it is inorganic, as well as fitting the other requirements for a mineral. However, sugar comes from a plant therefore it is not inorganic so it can not be classified as a mineral
What crystal systems exist within minerals
cubic, tetragonal, hexagonal, orthorhombic, monoclinic, tridinic
What is a crystal
a solid in which the atoms are arranged in repeating patterns
What is magma
molten material that is found beneath the Earth’s surface
What two(2) minerals make up the majority of the Earth’s crust
oxygen and silicon
What are oxides
compounds of oxygen and a metal
ex. hematite and magnetite
What are carbonates
minerals composed of one or more metallic elements with a carbonate compound (CO3).
ex. calcite, dolomite, rhodochrosite
Colour test
sometimes caused by trace elements or compositions. least reliable test
luster test
differences in luster are caused by differences in chemical composition. How the mineral reflects light
texture est
how it feels. used in combination with other tests
streak test
colour when broken down and powdered after being rubbed on an unglazed porcelain plate. Can distinguish minerals that look the same. Streak rarely changes with weather and colour change on the whole mineral. Mineral must be softer thsn plate
Hardness test
How easily a mineral is scratched. Used with Moh’s scale. reliable. determined by arrangement of atoms
Cleavage/fracture
- a mineral that splits easily and evenly along one or more flat planes is said to have cleavage. To identify use number of cleaved planes and angles between them
- minerals that break with rough or jagged edges are said to have fracture
