(MODULE 2) MINERALS AND ROCKS Flashcards
a naturally occurring, inorganic, crystalline solid that has a specific chemical composition.
mineral
Mineral groups are defined by their ___ and ___.
composition and crystal structure
composition: ___ and ___
single element and compounds
naturally formed aggregates of minerals or mineral-like substances
rock
bonding through electron transfer caused by the attraction force between ions of opposite charge
ionic bonding
bonding through electron sharing
covalent bonding
bonding wherein atoms are closely packed and the electrons move freely throughout the crystal so as to hold the atoms together
metallic bonding
weak bonding between sheets
van der waals bonding
types of bonding arranged from weakest to strongest
1.
2.
3.
4.
- van der waals
- metallic
- ionic
- covalent
The three mechanisms that generate minerals and rocks are:
1. P___
2. C___
3. D___
- Precipitation of mineral matter from a solution
- Crystallization of molten rock by cooling
- Deposition as a result of biological processes
explain how precipitation of mineral matter from a solution occurs.
a drop in temperature and water loss through evaporation can cause the solution to reach saturation wherein ions bond to form crystalline solids (salts).
explain how crystallization of molten rock by cooling occurs.
When the magma is still hot, the atoms are very mobile. However, as the molten material cools, the atoms slow and chemically combine. The slower the cooling process, the larger and lesser the crystals would be.
explain how deposition as a result of biological processes occurs.
biological process of all sorts can supply mineral matter
The atoms in most solids are organized in regular, geometric patterns, called the ___.
crystal structure
Minerals with the same chemical composition but different structures
polymorphs
Only 12 elements occur in the continental crust. enumerate them.
- iron
- aluminum
- magnesium
- sodium
- calcium
- potassium
- oxygen
- silicon
9 to 12. others
Three mineral groups:
1.
2.
3.
- silicate minerals
- carbonate, phosphate, sulfate minerals
- oxide, sulfide, ore minerals
What is the difference between silicon and silica?
silicon is the element, silica is the compound of oxygen and silicon
silicon and oxygen combine to form the atomic framework for most common minerals on earth in the form of a ___.
silicon-oxygen tetrahedron
The 5 types of silicate structures are:
1.
2.
3.
4.
5.
- isolated silicate structure
- single-chain silicates
- double-chain silicates
- sheet silicates
- framework silicates
Silicate minerals that are structured so that none of the oxygen atoms are shared by tetrahedra have an isolated silicate structure.
An example of this is the common mineral olivine.
isolated silicate structure
this structure forms when two of a tetrahedron’s oxygen atoms are shared with adjacent tetrahedra to form a chain.
single-chain silicates
the most common pyroxene. It is an essential mineral in mafic igneous rocks. Augite is usually black, with stubby crystals.
augite
this structure forms when two adjacent single chains are sharing oxygen atoms.
double-chain silicates
___ is a generic name for fibrous aggregates of minerals. It doesn’t ignite or melt in fire.
Asbestos
in a ___, each tetrahedron shares three oxygen atoms to form a sheet.
the mica group and clay group contain this structure.
sheet silicate structure
the ___ group is distinguished by their perfect basal cleavage, which means that they are easily split into thin, often transparent sheets.
muscovite and biotite belong in this group.
mica
The ___ minerals represent an important sub-group of the sheet silicates. The term ___ is used to denote particular mineralogical properties, in addition to a ___. It has the tendency to develop ___ when mixed with water.
1-2. clay
3. small particle size
4. plasticity
COMMON CLAY MINERAL GROUPS
formed by the decomposition of feldspar (e.g. granite). It is used in china clay, manufacture of pills, and has low compressibility and high friction angle.
kaolinite
COMMON CLAY MINERAL GROUPS
formed by the alteration of basic igneous rocks containing silicates rich in Calcium and Magnesium. it has high compressibility.
Can swell significantly by the adsorption of water, making it an expansive clay.
smectite or montmorillonite
When all four oxygen ions are shared by adjacent tetrahedra, a ___ is formed. This is the strongest of the silicate minerals.
Feldspar and Quartz are examples of framework silicates.
framework silicate structure
FRAMEWORK SILICATES
the most abundant mineral group in earth’s crust, it accounts for about 60 percent of all minerals in the continental crust.
its two most common members are orthoclase and plagioclase.
feldspar
FRAMEWORK SILICATES
the second most abundant mineral in the earth’s continental crust, after feldspar. found in many colors.
quartz
NON-SILICATE MINERALS
common minerals of this group contain calcite, aragonite, and dolomite.
what is this group?
carbonates group
NON-SILICATE MINERALS
apatite is the most common mineral of this group.
what is this group?
phosphates group
NON-SILICATE MINERALS
two common minerals in this group are gypsum and anhydrite. minerals in this group are used in the manufacture of some cement and a source for sulfuric acid.
what is this group?
sulfates group
ORE MINERAL GROUP
this subgroup consists of pyrite (fool’s gold), galena (primary ore mineral of lead), and sphalerite (a major ore of zinc)
what is this subgroup?
sulfides
ORE MINERAL GROUP
this subgroup consists of magnetite (natural magnet) and hematite.
what is this subgroup?
oxides
Although ___ is generally the most conspicuous characteristic of any mineral, it is considered a diagnostic property of only a few minerals.
color
The color of a mineral in powdered form and is often useful in identification.
A mineral’s ___ is obtained by rubbing it across a plate (a piece of unglazed porcelain) and observing the color of the mark it leaves.
streak
metallic minerals generally have a ___ streak, whereas minerals with nonmetallic luster have a ___ streak.
- dense, dark
- light-colored
The quality and intensity of light that is reflected from the surface of a mineral.
luster
A ___ luster gives a substance the appearance of being made of metal.
metallic
___ is more common. The most important type is glassy (also called vitreous) luster, which gives a substance a glazed appearance, like glass or porcelain.
nonmetallic luster
Metallic materials that developed a dull coating or tarnish when exposed to the atmosphere are said to have a ___.
submetallic luster
One of the most useful diagnostic properties is ___, a measure of the resistance of a mineral to abrasion or scratching.
hardness
A numerical value of hardness can be obtained by using the ___, which consists of 10 minerals arranged in order from 1 (softest) to 10 (hardest).
Mohs scale of hardness
The ___ of a mineral is a set of faces that have a definite geometric relationship to one another.
crystal form
a ___ is a breakage surface, whereas a ___ is a growth surface.
- cleavage surface
- crystal surface
the ability of a mineral to break along a preferred plane.
cleavage
a mineral tends to break along a cleavage surface due to the bonding between atoms there being ___.
weaker
the way a substance breaks where not controlled by cleavage.
fracture
minerals with no cleavage commonly have an ___ fracture.
irregular
some minerals break along curved fracture surfaces known as ___. these look like the inside of a clam shell.
conchoidal fractures
the ratio of a mass of substance
