Powerpoint for Earth and Life Science - Minerals

1. MINERALS
Prepared by: Engr. Ariel S. Motas
Engr. Andreana Amor M. Gulay

2. MINERALS?
• Minerals are naturally occurring inorganic solids with crystalline
structure, and chemical composition which may be fixed or vary within
certain limits. They are considered as natural because they are formed
by natural geological processes. Minerals are the basic building blocks
of rocks.
• Elements are the basic building blocks of minerals.

3. CHARACTERISTICS OF MINERALS
1. naturally occurring - a product of Earth’s natural processes
2. inorganic- it must be product of Earth’s physical processes.
3. homogeneous solid - minerals should have definite volume and rigid
shape
4. definite chemical composition - represented by a chemical formula
5. orderly crystalline structure - atoms of minerals are arranged in an
orderly and repeating pattern

4. How Minerals Form?
1. Crystallization from magma
2. Precipitation from aqueous solution (i.e., from hot water flowing
underground, from evaporation of a lake or inland sea, or in some cases,
directly from seawater) and gaseous emanations (e.g., in volcanic regions)
3. Pressure and temperature (Metamorphism)
4. Hydrothermal solutions

5. PROPERTIES OF MINERALS
1. Luster – the quality and intensity of reflected light exhibited by the
mineral.
a. Metallic - generally opaque and exhibit a resplendent shine
similar to a polished metal.
b. Non-metallic – vitreous (glassy), adamantine
(brilliant/diamond-like), resinous, silky, pearly, dull (earthy),
greasy, among others.
Galena (left) has a metallic luster, Amber (middle) is resinous, and
quartz (right) is glassy

6. PROPERTIES OF MINERALS
2. Cleavage is the tendency of a mineral
to cleave, or break, along flat, even
surfaces.

7. PROPERTIES OF MINERALS
3. Fracture - the uneven breakage of a mineral

8. PROPERTIES OF MINERALS
4. Color – property used to identify minerals easily. It is the result of the
way minerals absorb light. This is the most obvious property but it is the
least diagnostic.
For example, several minerals are green in color – olivine, epidote,
and actinolite. Minerals can also take on several different colors if there
are impurities depending to its chemical composition such as quartz,
which can be clear, smoky, pink or purple. Also, the mineral’s crystal
composition and structure can produce color. Hence, color is not a best
way to identify a mineral.

9. PROPERTIES OF MINERALS
5. Streak – color of the mineral in
powder form.
6. Crystalline structure
7. Diaphaneity/amount of transparency - ability to allow light to
pass through it.
8. Luster - how light is reflected off a surface

10. PROPERTIES OF MINERALS
9. Hardness – it is the measure of
the resistance of a mineral (not
specifically the surface) to
scratching. To measure the
relative hardness of minerals, the
Mohs Scale is used.

11. ROCK-FORMING MINERALS
• Minerals undergo different geological processes and become part of or
develop into rocks, in which case they become known as rock-forming
minerals. These are minerals that common and abundant in the Earth’s
crust; one making up large masses of rocks.
• Not all rock-forming minerals contains various types and amounts of
minerals that are useful to man. If the minerals found in these rocks
are rich with one or more useful mineral materials, they are referred to
as mineral resource. Most of the mineral resources used as raw
materials for buildings and structures that require the application of
various processes before they can be used. However, some materials do
not need or require little processing such as gemstones.

12. Example of ROCK-FORMING MINERALS
• Topaz – used as a gemstone in jewelry.
• Quartz – makes an excellent gemstone
• Talc – used as an ingredient in ceramics, paper, pain, roofing, plastics
and cosmetics, and variety of other assorted uses such as making
rubber and plastics.
• Pyrite - used to be an important ore for the production of sulfur and
sulfuric Acid. The most important use of pyrite is as an ore of gold.