Name ____________________________
Date _______________
Minerals
1. What is a Mineral?
A mineral is:
a. naturally occuring
b. inorganic
c. solid
d. has a crystal pattern
e. definite chemical composition and physical properties
2. Covalent bonds are bonds between atoms that are held together by the
sharing of electrons . Covalent bonding is common between nonmetals.
Ex) CO2, SiO4, NH4, and H2O
a. The goal of all atoms is to look like a noble gas.
GOAL:
SHARING:
3. Ionic bonds are bonds between atoms that are held together by the
transferring of electrons. Ionic bonding is typical between metals and
nonmetals.
Ex) NaCl, LiF, and KBR (salts)
a. Stealing an electron is better than sharing. Once an atom loses or
gains an electron, then it is now called an ion.
b. Ions (ionic) act like magnets, and have a strong bond.
STEALING (transfer):
4. Metallic bonds are bonds between metals atoms that are held together
by freely moving electrons. This is why copper (metal) wire is used in the
transfer of electricity (electrons).
5. Mineral formation occurs in
a. lava and magma
b. evaporating liquids
c. changes due to heat and/or pressure
6. Crystal Structure
a. Crystals are minerals whose atoms are arranged in a regular pattern.
Ex. diamonds, halite (salt), and quartz
b. Types of crystals:
1) Cubic (also called isometric) - halite, diamonds
2) Orthorhombic - sulfur, topaz
3) Tetragonal – chaclopyrite
4) Triclinic – turquoise
5) Monoclinic – gypsum, borax, sugar (not a mineral)
6) Hexagonal - quartz, graphite, calcite
7. The Silica Tetrahedron (plural = tetrahedra)
a. Silicates are compounds with the elements, silicon and oxygen, plus
one or more metals.
b. More than ninety percent of the minerals in Earth’s crust are
silicates.
c. The silica tetrahedron is the basic unit of silicates with one silicon
atom having covalent bonds with four oxygen atoms.
4 oxygen atoms
silica tetrahedron:
A small silicon atom hidden
in the middle of the oxygen
atoms (a good fit)
8. Arrangements for Silica Tetrahedra
a. Single tetrahedra – Individual silica tetrahedra ionically bonded with
iron and magnesium atoms.
Ex. olivine
b. Single chains – Chains of tetrahedra by covalently bonding two of the
four oxygen atoms with other tetrahedra. Chains are ionically bonded
together with metals.
Ex. pyroxene
c. Double chains – Chains of tetrahedra by covalently bonding two and
three of the four oxygen atoms with other tetrahedra. Ionically
bonded with metals.
Ex. Hornblende (amphibole)
d. Sheets – Sheets of tetrahedra by covalently bonding three of the
four oxygen atoms with other tetrahedra. Ionically bonded with
metals.
Ex. mica
e. Network of tetrahedra – All four oxygen atoms are covalently bonded
with other tetrahedra.
Ex. Quartz, feldspar
Resources and Mineral Identification
I.
Using Resources
1. Most of the metal in furniture, vehicles, and buildings is iron or steel. These
metals originally come from ore.
a. An ore is a mineral from which a metal or nonmetal can be extracted
profitably. Copper and aluminum ores are some examples.
2. Coal and petroleum products are used as fuels, as well as in the manufacture of
plastics, medicines, paints, and cosmetics. Glass is made from _sand .
3. Sand and gravel are used to make roads, and we combine them with limestone to
make concrete.
4. The amount of mineral resources is limited.
II.
Minerals
1. A mineral is a naturally occurring inorganic solid with well-defined physical and
chemical properties.
a. Some minerals are chemical elements or compounds, such as diamond (C) and
quartz (SiO2).
2. Rocks are formed from one or more minerals.
3. Although thousands of minerals have been identified and classified, less than a
dozen are commonly found. Clay, feldspar, quartz, and clacite make up the bulk of
rocks found near Earth’s surface.
4. Oxygen and silicon make up ____half___ of the _____mass_____ of these
minerals.
III. Identifying Minerals
Geologists usually identify minerals on the basis of their _____physical___ and
_______chemical________ properties.
1. Color - ____least reliable_______
a. Many minerals have a characteristic color, but because of
_____impurities_____, colorless and white minerals are often
_______discolored_________.
2. Luster - ____metallic or nonmetallic_____
a. Luster describes the way light is ______reflected_______ from the freshly
cut surface of a mineral.
b. Minerals with a ______metallic_____ luster have a hard, shiny look like
polished metal. This is because light is unable to penetrate the surface and
almost all the light is __reflected__. Non-metallic luster = _not all light is
reflected_______.
3. Streak
a. The test for streak is performed by _____rubbing____ a fresh corner of the
mineral across a white, unglazed streak plate. The streak is a
__powdered____ form of the mineral.
4. Crystal Structure
a. A crystal is a ______regularly_______ shaped ____solid_____ formed by an
ordered pattern of _____atoms_______.
5. Hardness
a. Minerals differ in hardness. You test for hardness by ____scratching_____
the unknown mineral with the edge or point of other minerals of known
_____hardness_____.
b. The geologist Friedrich Mohs created a _____scale____ of hardness that
uses relatively common minerals. On the Mohs’ scale, talc is the
____softest___ mineral with a hardness of 1, and diamond is the
___hardest_____ mineral, which equals __10_.
6. Cleavage & Fracture
a. If a mineral _____breaks____ readily along flat surfaces it shows cleavage.
b. Many minerals break along flat surfaces called ____cleavage
planes_________.
c. Cleavage planes are not always aligned with the sides of crystals. For example,
quartz has a six-sided crystal, but it breaks along _________________
surfaces, which is called ________________.
7. Density
a. Minerals also vary in density and _______specific gravity___________.
Specific gravity is a ratio of the density of a substance to the density of
water.
b. Water’s density is 1 gm/cm3. Therefore, a mineral with a density of 4 gm/cm3
has a specific gravity of _____four______.
This is
Moh’s Scale
of hardness.
It is a
relative
index based
upon the
hardness of
selected
common
minerals.
8. Radioactivity
a. Minerals, which contain ___uranium___ or ___radium__, are
radioactive. These minerals are found with a __geiger___ counter.
b. Radioactivity involves the emission of __alpha__, __beta__ particles,
and ___gamma___ rays from the atom nucleus. (unstable elements
breaking down into more stable elements)
c. An example of a radioactive mineral is _____zircon______.
9. Fluorescence
a. This occurs in some minerals when they absorb ____ultraviolet_____
light and give off _____visible_______ light.
b. If they continue to glow after the black light is turned off it is called
_____phosphorescence____________.
10. Magnetic Properties
a. Some metal ___ores__ have such a large concentration of ___iron___
in them, that they respond to magnet.
b. ___lodestone___, a kind of ___magnetite___, acts as a magnet.
11. Double Refraction
a. As light passes through ___calcite__ the light is split into __2_ rays.
Therefore two _____images______ are seen.
12. Acid Test
a. Only minerals that contain CO3 (__carbonate__) will react to acid.
b. The most common mineral of this type is __calcite__, whose formula is
______CaCO3_______.
c. When a drop of _____hydrochloric___ acid is placed on the mineral it
will _____bubble___ giving off __CO2__ gas.
d. There are three rock types that will react with acid due to their large
content of ____carbonate____. They are ___limestone___,
____dolomite_____, and ____marble_____.
CaCO3 +
2HCl
---> CaCl2
+ H 2O +
CO2
(Calcite) (Hydrochloric acid) (Calcium Chloride) (Water) (gas bubbles)
IV. Practice (refer to pages 11 & 16 of your ESRT’s)
1. What is the most abundance element in the Earth’s crust by mass?
a. Sodium
c. Aluminum
b. Oxygen
d. Hydrogen
2. What is the percent by volume of oxygen in the Earth’s crust?
a. 78 %
c. 94.04 %
b. 5.63 %
d. 33.0 %
3. Silicate minerals are made of both silicon and oxygen. By using page
11 of your reference tables, why do you think silicate minerals are the
most common minerals in the Earth’s crust?
__Silicon and oxygen are the most common minerals available_
_______________________________________________
_______________________________________________
4. Identify the mineral. Luster = nonmetallic, Hardness > 4, shows
Cleavage, white to pink Color.
____potassium feldspar_________
5. Identify the mineral. Luster = metallic, Hardness > 4, shows Fracture,
brassy yellow Color.
________pyrite______________
6. Identify the mineral. Luster = nonmetallic, Hardness < 5, shows
Cleavage, cubic and salty taste.
________halite_________________
7. Identify the mineral. Luster = metallic, Hardness < 4, shows Cleavage,
metallic silver Color.
_________galena________________
8. Which mineral is used in drywall?
________gypsum___________________