Unit 4 Day 3

Mineral Identification

VA SOL

n  a. properties including hardness, color and streak, luster, cleavage, fracture, and unique properties; and.

Objective

3. Define chemical and physical properties of minerals to include luster, hardness, cleavage, fracture, , color, specific gravity, and special traits.

Mineral Identification

n  With more than 3,000 minerals in Earth’s crust how does one go about identifying an mineral?

n  Geologists rely on several simple tests that are based on a mineral’s physical and chemical properties. It is usually best to use a of rather than just one to identify minerals
Mineral Properties

n  Color is one of the most noticeable but characteristics

n  Sometimes caused by the presence of or compounds

n  Streak is the color of the mineral when it is broken up into a and is a much more identification method because it rarely changes

n  Streak is easily determined by rubbing the mineral across an unglazed

n  Streak is used to distinguish from

n  Luster is the way a mineral from its surface and is caused by differences in mineral chemical compositions

n  Either or (dull, pearly, waxy, silky)

n  Texture describes how a mineral to the touch

n  Rough, smooth, ragged, greasy, soapy,

n  Hardness is a measure of how easily a mineral can be and is determined by the of it’s atoms.

n  The hardness scale is used to compare a sample to the hardness of known minerals

n  determines whether a mineral will split easily and evenly along one or more planes

n  has perfect cleavage in one direction

n  Halite has cleavage (3 planes)

n  Fracture means the mineral is tightly bonded and breaks with or edges

n  compares the weight of the mineral to an equal volume of water at 4 degrees C

n  Special Properties such as reflection and reactions to acids are also useful tools

n  fizzles when in contact with

n  Calcite also can cause

n  will attract iron

n  produces a rotten egg odor 8