Minerals Flashcards
What are minerals?
Naturally occurring elements and inorganic compounds whose composition can be expressed as a chemical formula.
What is a rock?
A compound or aggregate of many minerals.
What are the 5 characteristics shared by all minerals?
Natural, inorganic, crystalline, definite chemical composition, solid.
What are the 6 physical properties used to determine a type of mineral?
Colour, Streak, Hardness, Cleavage, Fracture, Lustre
What are the 5 special properties a mineral can have?
Magnetism, Double refraction, Fluorescence, Phosphorescence, Piezoelectric
What do white of colourless minerals contain?
Metallic elements largely from groups 1 and 2 of the periodic table
What do coloured minerals tend to contain?
Elements from the transition minerals
What does lustre depend on?
The mineral’s ability to reflect light
Name 7 terms used to describe a mineral’s lustre
Metallic, earth, adamantine, pearly, silky, resinous, vitreous
What are cleavage planes?
Planes of weakness in the mineral’s atomic structure
Why do some minerals fracture?
The bonds between the atoms are strong
What is the hardness of a nail, copper coin and compass point?
Nail- 2-2.5
Copper coin- 3
compass point-6
What is specific gravity?
The ratio of the mass of a mineral compared with the mass of an equal volume of water
What are minerals used to classify?
Sedimentary, igneous and metamorphic rocks
When does twinning occur?
It occurs when two or more crystals grow with different orientations from a common plane. One is usually a mirror image of the other.
