The document discusses the composition and characteristics of minerals that make up the Earth's crust. Minerals are naturally occurring substances composed of elements and ions bonded together. They are solid, inorganic compounds with defined chemical compositions. Common minerals include quartz, feldspar, calcite, and many others. Minerals can be classified based on their chemical makeup and physical properties such as color, hardness, crystal structure, and streak. Together minerals constitute the solid rocky materials that form the Earth's crust.
2. MINERALS
Minerals are naturally occurring
substances that build up the
Earth’s Crust. Minerals are made
up of different Ions bonded
together. Ions are charged atoms.
Cations are positive ions and
Anions are negative ions. Some
common Cations are Si, Al, Fe,
Ca, Na, K and Mg while anions
are O and Cl.
3. CHARACTERISTICS OF
MINERALS
1. Minerals are Solids.
2. Minerals are Made of Chemical
Elements and Compounds.
3. Minerals have known Chemical
composition.
4. Minerals are inorganic in nature.
5. CLASSIFICATION OF MINERALS
- minerals can be classified based on
their chemical compositions and physical
properties.
1. Silicate minerals are those that contain
silicon and oxygen. They further classified
into “malfic silicates” and “felsic silicates”.
a. Malfic silicates generally contain Fe or
Mg and are dark in color. Examples;
Olivine, Pyroxene, Amphibole and Biotite
mica.
b. Felsic Silicate contains K, Na and Al and
6. Malfic silicates - silicates that are dark in color.
Examples; Olivine, Pyroxene, Amphibole and
Biotite mica.
7. Felsic Silicate – silicate that are light in color.
Examples; feldspar, quartz, clay minerals, and
muscovite.
8. 2. Non Silicate minerals are those that do not
contain silicon. The most common group of non
silicate minerals are carbonates, halides and
sulfates.
Ex. Iodide, fluoride and sodium chloride.
9. 3. Metallic minerals are those that are made up
of heavy metallic elements. Examples; copper,
iron, gold, silver, chromium and nickel.
10. 4. Non metallic minerals lack the properties of
the metallic minerals, such as bright metallic
luster, hardness, density and good conductor of
heat and electricity. Examples; calcite, quartz,
talc and gypsum.
11. 5. Gem minerals are those that possess unique
bright colors and commonly used for jewelry.
Examples; jade, sapphire, ruby, opal and
garnet.
12. INDENTIFICATION OF MINERALS
Physical Properties of Minerals
1. Habit refers to the overall shape or growth
pattern of the mineral. Scientists use “equant”
“elongate” and “platy” to describe the habit of
minerals:
a. Equant – three dimensions of the mineral have
about the same length, like that of a cube or
sphere. Ex, Garnet shows an equant habit
b. Elongate – minerals form prismatic or prism-like
crystals that are thicker than needles as in a pencil.
Ex, Indicolite shows an elongated habit.
c. Platy – the minerals looks like a flattened and
thin crystal (like Plates) Ex, Wulfenite shows a platy
13. 2. Luster – refers to the quality of light reflected
from the exterior surface of the mineral.
The Luster Minerals can be Opaque,
Transparent, Dull, or Shiny.
Metallic luster is Opaque and very reflective.
Non metallic luster is Dull, Silky, greasy and
pearly.
3. Breakage of the Minerals; are classified into;
Cleavage – refer to the tendency of mineral to
break along very smooth, flat and shiny
surfaces.
Fracture – the tendency of the mineral to break
15. 4. Hardness – is a measure of the mineral’s
resistance to Scratching. Harder minerals
scratch softer minerals. Mohs’ Scale of Hardess
was created by Minerologist Friedrich Mohs in
1812.
5. Color varies in many minerals making it very
unreliable to set as a standard for identification.
Some minerals comes in just one color, while
others come in many colors and varieties.
6. Streak – refers to color of mark or powder left
by rubbing the mineral against a streak plate
(unglazed porcelain).
