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