Download MINERAL LAB

***MINERAL LAB***
A. A mineral is naturally occurring, inorganic substance with an orderly internal
atomic arrangement and a definite chemical composition.
B. Crystal face is the external expression of a mineral’s internal atomic structure.
C. Cleavage plane is a plane of weakness in the crystalline structure along which a
crystal will break.
D. Color is the result of impurities, however this color does not constitute a
fundamental difference in the varieties of Quartz.
E. Two different varieties of feldspar are Potassium (feldspar) and Plagioclase
(feldspar).
F. Color is one way to identify mineral content, but to have specific identification
chemical, optical, and x-ray analysis are needed.
G. Characteristics of Calcite:
a.
b.
c.
d.
Three directional cleavage not at right angles
Rhombohedral cleavage
Hardness of three
Reaction with HCL acid
H. Olivine is olive green in color and has aggregates of small glassy grains or
crystals.
I. Olivine is an important mineral in igneous rocks. (Basalt, Gabbro, Periodotite)
***Igneous Rock Lab***
A. The thickness of a basalt flow depends on the viscosity of the lava. Viscosity is
dependent upon the amount of dissolved gasses as well as temperature and
composition. Lava’s that are pooled into lakes will be the thickest.
B. The difference between Granite and Diorite is composition. Diorite is comprised
mostly of Plagioclase and Ferromagnesium minerals. Granite contains Potassium
Feldspars, Quartz and Sodium-Plagioclase. The texture of the rocks is the same.
C. Vesicles in the Basalt are a result of entrapped gas bubbles rising in the cooling
lava. They are usually concentrated near the top of a flow, below the earlysolidified crust.
D. All Granites have two diagnostic characteristics:
1. Composition—Quartz, Potassium (K) Feldspar, and Sodium (Na)
Plagioclase
2. Texture—Phaneritic
E. Basalt is the most common rock in the ocean crust. It is derived from the mantle
when there is a partial melting of the upper mantle.