Mineral Review
Mineral – a naturally occurring, inorganic solid that has a crystal structure and a
definite chemical composition.
Characteristics (inside-genetic make-up)
Solid – definite shape and volume
Inorganic – never alive
Naturally Occurring – no help from humans
Crystalline Structure – particles of a mineral line up in a pattern that repeats
Chemical Composition – compounds that are made up of one or more elements
Properties (outside - physical) How minerals are identified
Streak – the color of the powdered form of the mineral
Luster – way a mineral reflects light – metallic, nonmetallic, glassy, dull, and shiny
Hardness – how easily a mineral scratches materials – Mohs Hardness Scale
Cleavage – minerals breaks along smooth, flat surface
Fracture – minerals that break at random with rough or jagged edges
Color – color and appearance are not enough to distinguish minerals
Crystal – solid with atoms arranged in an orderly, repeating pattern
Crystals form
1) Colling of hot, liquid rock called magma causing compounds to combine
a. Magma cools slowly = crystals are large (intrusive igneous)
b. Magma cools quickly = crystals are small (extrusive igneous)
2) The evaporation of water that has minerals dissolved in it
Special Properties – Florescent, magnetic, optical properties, chemical reactions,
taste, radioactive
Mineral Compositions and Groups – There are 90 elements that make up Earth’s
Crust. About 98% of the crust is made up of only 8 of these elements (Oxygen,
Silicon, Aluminum, Iron, Calcium, Sodium, Potassium, and Magnesium)
How are minerals grouped? - Grouped by elements – Silicon and oxygen are the two
most abundant elements in the Earth’s crust, the minerals are called silicates.