Exam 1
This is a weathered, oxidized caprock that forms at the surface of sulfide ore deposits, often containing iron oxides like hematite and limonite.
What is a gossan?
These two physical properties are consistent and common to all feldspars.
What is Hardness and Cleavage?
Minerals with these type of bonds are characterized by physical properties including: moderate hardness and SG, high melting points, poor conductors of electricity and heat, and high symmetry due to uniform charge distribution (ex. fluorite, silicates).
What are ionic bonds?
This value is determined by the density and type of crystal structure. Dense High SG minerals have slow velocity, resulting in a high ____.
What is the value (n)?
Minerals such as gypsum, anhydrite, barite, celestite, and anglesite belong to this chemical group.
What is sulfates?
This environment is characterized by ascending gas and fluids at high temperature and pressures. It lies deep within the subsurface at the base of a sulfide dominant ore deposit.
What is the hypogene zone?
This group of minerals is able to absorb water between structural layers, causing it to swell; it becomes compact when the water is removed.
What is smectite clay?
This rule describes the equation: EVB = cation charge/CN where evb is electrostatic valence bond and CN is the coordination #.
What is Pauling's 2nd Rule: The electrostatic valency principle?
Looking at the epsilon and omega to determine the optic sign is useful for these crystal systems.
What is Hexagonal and Tetragonal?
These are coating or encrustations of secondary minerals (weathering products) on primary sulfides or arsenides.
What are blooms?
You would expect to find oxides, hydroxides, carbonates, and sulfates in this environment.
What is the supergene zone?
These 3 Al2SiO5 polymorphs occur as important index minerals in metamorphic rocks.
What is Kyanite, Andalusite and Sillimanite?
In this crystal system, the 4-fold axis is the c-axis, the bisectors of the angles between the a axes are 2-fold axes.
What is the tetragonal system?
This is known as the difference in refractive index between epsilon and omega directions.
What is Birefringence (N-n)?
This is characterized by secondary mineralization associated with weathering and cool descending groundwater movement (oxides, hydroxides, hydrous carbonates).
What is supergene deposits?
This habit is characterized by a treelike or mosslike form.
What is Dendritic?
This mineral group will dry out at very high-grade metamorphic conditions (Granulite Facies).
What is amphibole?
These are the set of three/four integers used to describe the orientation of planes in a crystal lattice.
What are miller indices?
These are the indices of refraction associated with X,Y, and Z for biaxial minerals.
What is alpha, beta, gamma?
This mineral group has cleavage at 124 and 56 degrees, and a hardness of 5-6.
What is amphibole?
This type of breakage occurs when a mineral splits along planes of weakness due to external stress, twinning, or exsolution.
What is Parting?
These two ferromagnesian minerals occur as minor components in granites and granodiorite.
What is hornblende and biotite?
This crystal class is described as follows: three mirror planes intersect on the 3-fold axis of the crystal (ex. tourmaline).
What is 3m?
This is the angle between the optic axes.
What is 2V?
This type of feldspar typically appears white or light-colored.
What is sodium-rich feldspar?