Chapter 2 - Mineralogy Flashcards
The study of minerals.
Mineralogy
The basis for the formation of rocks.
Minerals
It makes up the minerals and minerals make up rocks.
Matter (elements)
A naturally occurring combination of specific elements arranged in a particular repeating three-dimensional structure or lattice.
Mineral
These determine the physical properties of minerals.
Chemical formula and the Crystal lattice
The types and proportions of the chemical elements
Chemical Formula
The geometry of how the atoms are arranged and bonded together)
Crystal Lattice
Ten minerals make up most of the volume of the earth’s crust
Plagioclase, quartz, orthoclase, amphibole, pyroxene, olivine, calcite, biotite, garnet, and clay
Readily observable and certainly obvious, but it is usually less reliable than other physical properties.
Color
Describes the reflection of light off a mineral’s surface.
Luster
The standard names of luster
Metallic, glassy, pearly, silky, greasy, and dull
The color of a mineral’s powder. A more reliable property than color because this does not vary.
Streak
The strength with which a mineral resists its surface being scraped or punctured.
Hardness
In working with hand samples without specialized tools, mineral hardness is specified by __________.
Mohs hardness scale
The tendency of a mineral to break along certain planes to make smooth surfaces.
Cleavage
The cleavage properties of a mineral are described in terms of ________.
The number of cleavages and, if more than one cleavage, the angles between the cleavages
The possible number of cleavages a mineral may have.
1, 2, 3, 4, and 6
A break in a mineral that is not along a cleavage plane.
Fracture
The way a thick piece of glass breaks with concentric, curving ridges on the broken surfaces.
Conchoidal fracture
A standard term for fractures that do not exhibit any of the qualities of the other fracture types.
Irregular Fracture
Mineral glows under ultraviolet light
Fluorescence
A mineral is attracted to a magnet
Magnetism
Mineral gives off radiation that can be measured with a Geiger counter
Radioactivity
Bubbles form when the mineral is exposed to a weak acid
Reactivity
Some minerals have a distinctive smell
Smell
Some minerals taste salty
Taste
Based on the polyatomic anion, which has a tetrahedral shape.
Silicates
Most minerals in the earth’s crust and mantle are ____________.
Silicate Minerals
The silicate tetrahedra are separated from each other and bonded completely to nonsilicate atoms.
Nesosilicates
The silicate tetrahedra are bonded in pairs.
Sorosilicates
The silicate tetrahedra are joined in rings. Beryl or emerald is an example.
Cyclosilicates
The tetrahedra are bonded at three corners to form flat sheets. Biotite is an example
Phyllosilicates or sheet silicates
The silicate tetrahedra are bonded in single chains. Pyroxenes is an example
Single-chain inosilicates
The silicate tetrahedra are bonded in double chains. Amphiboles is an example
Double-chain inosilicates
All corners of the silicate tetrahedra are bonded to corners of other silicate tetrahedra, forming a complete framework of silicate tetrahedra in all directions. Feldspar, the most common mineral in earth’s crust, and quartz are the examples
Tectosilicate
These are based on the sulfide ion
Sulfides
These are based on the carbonate ion
Carbonates
This tends to dissolve relatively easily in water, especially acid water, and natural rainwater is slightly acid
Carbonate Minerals
These are based on the oxygen anion
Oxides
These have a halogen element as the anion, whether it be fluoride, chloride, bromide, iodide, or astatide.
Halides
These have the polyatomic sulfate ion, as the anion.
Sulfates
These have the polyatomic phosphate ion, as the anion.
Phosphates
These are made of nothing but a single element.
Native Elements
Ways of Identifying Minerals
- Look at it closely on all visible sides to see how it reflects light
- Test its hardness
- Identify its cleavage or fracture
- Name its luster
- Evaluate any other physical properties necessary to determine the mineral’s identity
Formation of Minerals
- Formation from Hot Materials
- Formation from Solutions
