please don't forget to like and leave your comments. this presentation is about rocks and minerals, grade 11, earth and life sciences; senior high school

1. Minerals and
Rocks

2. Learning Outcomes
• I can identify the physical properties of minerals
• I can identify the chemicaL properties of
minerals.
• I can identify some minerals and their uses.
• I will appreciate the importance of conserving
mineralsI can identify and describe the different
properties of rocks.

3. Minerals
Minerals - naturaly formed, generally inorganic, crystalline,
solid and has a definite chemical composition.
building blocks of rocks
Mineralogy - Branch of Geology that deals with the study of
Minerals
There are about 3,000 known minerals, of that 20 minerals
make up most rocks

4. Physical Properties of Minerals
- can be used to easily identify a mineral.
1. Color
2. Streak
3. Hardness
4. Cleavage and Fracture
5. Crystalline structure
6. Transparency or diaphaneity
7. Magnetism
8. Tenacity
9. Luster
10. Odor
11. Specific Gravity

5. Physical Properties of Minerals
1. Color - usually the property used to identify minerals
easily. It is the result of the way minerals absorb light.
Some Colors of Quartz

7. Physical Properties of Minerals
2. Streak - is the color of the mineral in powder form.
For opaque minerals, if you rub the sample across a
streak plate, it will leave a colored powder. This
streak is distinctive for minerals and is used to identify
minerals.

8. Varieties of Hematite – all same color streak

10. Physical Properties of Minerals
3. Hardness - refers to the
measure of the mineral’s
resistance to scratching.
Minerals with higher
numbers will scratch
minerals below. To measure
the relative hardness of
minerals, the Moh's scale is
used.

11. Physical Properties of Minerals
4. Cleavage and Fractures - used to describe how minerals
break into pieces.
Some minerals split along flat surfaces (called
cleavage planes) when struck hard--this is called
mineral cleavage
Other minerals break unevenly along rough or curved
surfaces--this is called fracture
A few minerals have both cleavage and fracture (
mica )

13. FLUORITE
HALITE
Halite (NaCl)
Fluorite (CaF2)
Cleavage – due to weak bonds in the crystal
structure

15. Cleavage
BIOTITE
MUSCOVITE

16. Rose Quartz – Conchoidal Fracture

17. Conchoidal Fracture - Quartz
Obsidian

19. Physical Properties of Minerals
5. Crystalline structure - crystal lattice, tells how a
mineral’s crystals are arranged. A hand lens is a
necessary tool in checking for crystalline structure.
crystal solid - form regular repeating three
dimensional crystal lattice
amorphous solid - forms aggregates that have
particular order or arrangement

20. Physical Properties of Minerals
6. Transparency or diaphaneity - indicates the extent of
light that can pass through the mineral.

21. Physical Properties of Minerals
7. Magnetism - indicates the ability of a mineral to attract
or repel other minerals.
8. Tenacity - level of resistance or reaction of minerals to
stress such as crushing, bending, breaking, or tearing.
9. Luster - refers to the reaction of a mineral to light. It
determines how brilliant or dull the mineral is.
Categories: Metallic or Non-metallic
Metallic – luster of metal – shines like a hard metal
Many non-metallic minerals are SHINY because they
are transparent or semi-transparent

22. Examples of metallic luster

23. Pyrite (FeS2)
Galena (PbS)
More Examples of Metallic Luster
PYRITE
GALENA

24. Example of non-metallic luster
• Vitreous--quartz

25. Example of non-metallic luster
• Silky--example plagioclase feldspar

26. Non-metallic and metallic luster – earthy
hematite – metallic hematite

27. Physical Properties of Minerals
10. Odor - -a distinct smell of a mineral that is usually
released from a chemical reaction when subjected to water,
heat, air or friction.
11. Specific Gravity - is a measure of the density of a
mineral. Determines how heavy the mineral is by its weight
to water.

28. Chemical Properties of Minerals
Another way of identfying and classifying minerals is
according to their chemical compositon. This classification
was first used in 1848 by James Dwight Dana (1813-
1895).
1. Silicate class 5. Oxide class
2. Carbonate class 6. Sulphide class
3. Sulphate class 7. Phosphate class
4. Halide class 8. Native element class

29. Chemical Properties of Minerals
1. Silicate Class - largest and most abundant group
containing Si and O with some Al, Mg, Fe, and Ca. (Ex.
feldspar, quartz, pyroxene, mica, garnet. olivine and
amphibole

30. Chemical Properties of Minerals
2. Carbonate class - mostly found depositedin marine
environments.
3. Sulphate Class - forms in areas with high
evaporation rates and where salty waters slowly
evaporate.
(Ex. anhydrite, celestine, barite, gypsum)
4. Halide class - contains natural salts includes fluorite,
halite, sylvite and sal ammoniac components. Usually
form in lakes, and sal ammoniac components.

31. Chemical Properties of Minerals
• 5. Oxide class - is a diverse class. In science,
these minerals are important as thet carry histories
of changes in Earth's magnetic field. They are
formed as precipitates close to Earth's surface or
as oxidation products of minerals during the
process of weathering.
• 6. Sulphide class - has important metals such as
copper, lead and silver which are considered
economically significant.

32. Chemical Properties of Minerals
7. Phosphate class- contains minerals with
phosphorus. Considered as important biological
mineral found in teeth and bones in many
animals.
8. Native element class - contains metals and
intermettalic elements, semimetals nonmetals
or natural alloys and constituents of a few rare
meteorites.

33. Rocks
- are natural substances consisting of
aggregate minerals clumped together with
other materials through natural processes.
Rocks, like some materials, are products of
a natural cyclic process.

34. Properties of Rocks
1. Rocks exhibit different properties. As to color,
rocks may be dark, light, reddish, ggray,
brown, yellow o even black.
2. Rocks differ in texture: some are fine, others
are rough.
3. Some are glossy in appearance and smooth
to touch.
4. Most rocks are hard, others are brittle.

35. Classification of Rocks
1. Igneous rocks - derived from the Latin word ignis
meaning “fire” are crystallized from magma or
molten or partially molten volcanic materials that
came from within Earth. Magma rises from the
asthenosphere or at the base of the crst through
volcanoes or any cracks and fisures on Earth's
surface. When it reaches the sface of Erth. thr
molten volcanic material is called lava. (granite,
rholite, diorite, andesite, basalt, gabbro)

36. Importance of Igneous Rocks
• contains fossils that are
evidences of geologic
past
• coal, petroleum and
natural gas are major
energy source
• iron , aluminum and
manganes are used in
the construction
industry.

37. Classification of Rocks
2. Sedimentary rocks - frm the root
word sediments which means
“remaining particles” are rocks that
have formed from the deposition of
different materials on Earth's surface.
They come from preexistinf rocks or
pieces of dead organisms that have
been “lithified” or cemented by natural
processes. (limestone,
conglomerate, haite, calcite,
sandstone, limestone and gypsum)

38. 2 major groups of sedimentary rocks
1. clastic - form from the accumulation and
lithification of sediments derived from the
breakdown of pre-existing rocks. They are further
classified according to dominant grain size.
2. nonclastic - derived from sediments that precipitated
from concentrated solutions (e.g. seawater) or from the
accumulation of biologic or organic material (e.g. shells,
plant material). They are further classified on the basis
of chemical composition.

39. Classification of Rocks
3. Metamorphic rocks - meta
means “change”” and morph
means “form” are rocks derived
from gneous or sedimentary
rocks that were exposed to high
pressure, high temperature or a
combination of both, deep below
te surface of Earth. Because of
this exposure, some of the
minerals in these roocks
undergo chemical and physical
changes.