learning

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
Physical Properties of Minerals
- can be used to easily identify a mineral.

4. 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

9. Varieties of Hematite – all same color streak

12. Physical Properties of Minerals

13. 3. Hardness - refers to the measure of the mineral’s

14. resistance to scratching. Mineralswith higher numbers
will scratch minerals below. To measure the relative
hardness of minerals, the Moh's scale is used.
Physical Properties of Minerals
4. Cleavage and Fractures - used to describe how minerals
break into pieces.

15. 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
)

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

18. HALITE
FLUORITE

20. Cleavage

21. MUSCOVITE
BIOTITE

22. Rose Quartz – Conchoidal Fracture

23. Conchoidal Fracture - Quartz

24. Obsidian

26. 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

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

28. 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

29. Physical Properties of Minerals
Many non-metallic minerals are SHINY because they
are transparent or semi-transparent

30. Examples of metallic luster

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

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

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

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

35. 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.

36. 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

37. 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

38. 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)

39. Chemical Properties of Minerals
4. Halide class - contains natural salts includes fluorite,
halite, sylvite and sal ammoniac components. Usually
form in lakes, and sal ammoniac components.
• 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.

40. Chemical Properties of Minerals
• 6. Sulphide class - has important metals such as
copper, lead and silver which are considered
economically significant.
7. Phosphate class- contains minerals with
phosphorus. Considered as important biological
mineral found in teeth and bones in many
animals.

41. Chemical Properties of Minerals
8. Native element class - contains metals and
intermettalic elements, semimetals nonmetals or
natural alloys and constituents of a few rare
meteorites.

42. 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.
Properties of Rocks

43. Classification 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.

44. 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)
Importance of Igneous Rocks

45. Classification of Rocks
• contains fossils that are evidences of geologic past

46. • coal, petroleum and natural gas are major energy
source
• iron , aluminum and manganes are used in the
construction industry.

47. Classification of Rocks
2. Sedimentary rocks - frm the root word sediments which means

48. “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)
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.

49. Classification of Rocks
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.

50. 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

51. Classification of Rocks
undergo chemical and physical changes.