1. Suez University
Faculty of Petroleum & Mining Engineering
Minerals and Rocks
Student
Belal Farouk El-saied Ibrahim
Class / III
Section / Engineering Geology and Geophysics
The Reference / Basic Pet. Geology
(P.K.Link
Presented to
Prof. Dr. / Shouhdi E. Shalaby
)

2. Main Topics



Minerals.
Rocks.
Igneous
Sedimentary
Metamorphic
Rock cycle.

3. What are minerals?



All rocks are composed of
minerals
Minerals are naturally
occurring, inorganic,
crystalline solid with a
definite chemical
composition found on
Earth.
There are about 3500
known minerals

4. About 20 minerals make up more than 95%
of all of the rocks in the Earth’s crust

5. Composition of the Earth’s
Crust

Eight Elements that make up over 98%
of Earth’s Crust
-Oxygen (O)
-Silicon (SI)
-Aluminum (Al)
-Iron (Fe)
-Calcium (Ca)
-Sodium (Na)
-Potassium (K)
-Magnesium (Mg)

6. MINERAL PROPERTIES
Physical properties of minerals are dictated by the nature of
the underlying atomic structure, nature and arrangement of
chemical bonds, and energy levels of valence electrons.








Color
Luster
Hardness
Streak
Density
Crystal Shape
Cleavage and Fracture
Special Properties

7. Color

Usually the first and most easily observed
-Some minerals are always the same color
-Some minerals can have many colors
ROSE QUARTZ
QUARTZ
SMOKY QUARTZ

10. Luster

General
appearance of a
mineral surface in
reflected light
Glassy-Obsidian

11. Hardness: MOH’S Hardness Scale (NOT absolute):
Talc
Gypsum
Calcite
Fluorite
Apatite
Orthoclase
Quartz
Topaz
Corundum
Diamond
1
2
3
4
5
6
7
8
9
10

15. External Crystal Form:a solid plane in which the
atoms are arranged in orderly, repeating patterns
A. cubic
B. tetragonal
C. hexagonal
D. orthorhombic
E. triclinic
F. monoclini
(some minerals do not show well-developed crystals).
Fluorite

17. CUBIC
HALITE
TETRAGONAL HEXAGONAL
WULFENITE
BERYL
ORTHORHOMBIC MONOCLINIC
TANZANITE
GYPSUM
TRICLINIC
MONTEBRASITE

18. Crystal Form
Quartz

19. Crystal Form 02.15b
Fig.
Feldspar

20. CLEAVAGE: splitting along preferred directions due to weak
bonds within the atomic structure. Cleavage is described as perfect,
good, poor.
This is a property of crystals – be careful that you are looking at
crystals and not crystal aggregates.
Cleavages can be confused with crystal faces – can often see
cleavage planes perpendicular to crystal faces.
Some crystals do not show cleavage due to similar bond strengths
throughout the crystal structure. However, a crystal can have 1, 2,
3… directions of cleavage. It is important to note: (i) the number
of cleavage directions, and (ii) their angular relationship:
1 direction; 2 directions at 90˚; 2 directions, inclined;
3 directions, cubic; 3 directions, rhombohedral;
4 directions, octahedral; 6 directions dodecahedral.

22. Planer Cleavage in Mica

23. Weak Bonding Yields Planer Cleavage

24. Amphibole Cleavage ~120/60°

25. Rhombohedral Cleavage in Calcite

26. Fracture: the way a substance breaks where not controlled
by cleavage. Described as: conchoidal,
irregular, splintery, blocky, hackly.
Specific Gravity: unitless property, defined by
mo u n
a f ss c
s _ t e
s
_ b
a
mo q_.o 2
a f e lv f H
s _ ao _
s
_ u l
_
O
Ice:
0.9
Quartz:
2.65
Most silicates: 2.5-3.0
Galena
7.5
Gold
19.3

27. Conchoidal Fracture in Glass

28. Special and Other Properties



Striations - Commonly found on plagioclase
feldspar. Straight, parallel lines on one or more
of the cleavage planes caused by mineral
twinning.
Magnetism - Property of a substance such that
it will spontaneous orient itself within a magnetic
field. Magnetite (Fe3O4) has this property and it
can be used to distinguish it from other nonmagnetite iron oxides, such as hematite (Fe 2O3).
Double Refraction - Seen in calcite crystals.
Light is split or refracted into two components
giving rise to two distinct images.

29. Plagioclase
striations

30. Calcite Double Refraction

31. Special Properties





Magnetism (Magnetite)
Glowing under ultraviolet light (Fluorite)
Salty taste (Halite)
Smell (Sulfur)
Reaction to HCl (Calcite)

32. Magnetism
Fluorescence
Magnetite
Double Refraction
Calcite
Smell
Sulfur

33. Rocks

34. Rocks

Made of two or more different minerals
that have been:
 cemented together
 squeezed and heated together
 melted and cooled together.

35. Types of Rocks



Igneous
Sedimentary
Metamorphic

36. Igneous Rocks



Magma- molten material underground
Lava- magma that reaches the surface
Igneous rocks are formed from magma
that has cooled and hardened either
beneath the surface or from a volcanic
eruption

37. 2 Ways to Form Igneous Rock


Intrusive Igneous
Rocks - form when
magma hardens
beneath Earth’s
surface
Magma intrudes into
existing rocks


Extrusive
Igneous Rocksform when lava
hardens on the
surface of the Earth
Extruded onto the
surface
rhyolite
granite

38. Classification of Igneous Rocks


Composition -refers to the minerals that
make up the rock
Texture -shape, size, arrangement and
distribution of minerals that make up the
rock

39. Composition
Bowen’s Reaction
• N. L. Bowen studied mineral crystallization
and found out that minerals form at specific
times during that solidification process and
they generally form in the same order.

41. Textures

42. Textures

Glassy

Obsidian

Fine-grained
Basalt
Coarse-grained
Granite

Porphyritic
Granit

43. Sedimentary
Rocks

44. Sedimentary Rocks

Sediments = pieces of solid
material deposited on the Earth’s
surface.

45. Sedimentary Rock


Rocks that are composed of the
weathered remains of preexisting
rock, or plant and animal remains.
Sedimentary rocks commonly
originate from sediments laid down in
horizontal strata by water or wind.

46. Bedding planes
Beds
Horizontal Beds of Sedimentary Rock

47. Sedimentary Rocks

How is a sedimentary rock formed?

Sediments get compacted and
cemented together.

48. Sedimentary Rocks

Clastic – made from fragments of other
rocks, that have been transported,
deposited, then compacted and
cemented together.


Shale, sand, conglomerate, siltstone, breccia
Classified by the size of the fragments in the
rocks

49. 
Cemented Rocks
Clastic sedimentary rock – rocks
composed of weathered sediments:




Pebbles or gravel – usually quartz
Sand – usually quartz
Clay and silt – weathered feldspars and
mica :
held together by a natural cement

or by compaction of clay and silt.

51. Sedimentary rocks drop according to
size; larger particles fall first followed
by smaller particles

52. Clastics Rocks

Conglomerate

Sandstone

Mudstone

53. Conglomerate – cemented
sand, silt, and pebble
sediments. If large
fragments are angular this
rock is called a breccia.
Sandstone –
cemented quartz
sand grains.
Feels gritty.
Unfilled spaces
between grains
make most
sandstones
porous and
permeable to

54. Bedding planes
Shale – clay and silt sized particles
lithified by dehydration and compaction.
Note the cleavage at bedding planes.
Thumps when you tap it with a nail and,
moistened, it smells like damp earth.

55. Sandstone in the Pinnacle Desert,
Australia
Photo used with permission from Mike Jarvis, Naperville Central
HS, Naperville, IL

56. Chemical Sedimentary Rocks

Rocks formed either as precipitates
or as evaporites of dissolved
chemical sediments.

Rock salt, rock gypsum, some
limestones

57. Rock salt , the
mineral halite (NaCl),
left as an evaporite
as a shallow sea
evaporated.
Alabaster , the mineral
gypsum (CaSO 4 ), also
an evaporite.

58. Compact (or precipitate) limestone , the mineral
calcite (CaCO 3 ), precipitated from sea water as
evaporation increased concentration. Many
cavern systems are formed in this type of
limestone.

59. Sedimentary Rocks

Organic Rocks – formed from the
remains of plants and animals.


Shells of marine animals pile up,
compact and cement to create
fossiliferous limestone (coquina).
Sedimentary rocks are the only rocks
that contain fossils

60. Coquina – cemented
aggregate of geologically
modern shell fragments.
Fossiliferous limestone
– a cemented
aggregate of original
shell fragments, molds,
and casts of ancient
marine organisms.
Note fossil mold of a
shell in this specimen.

61. Peat , a mass of matted
together plant material
covered by H 2 O, which
impedes decay. H 2 and
O 2 are lost,
concentrating carbon.
Lignite , so called
“brown coal”, a soft
coal that forms when
peat is compressed
and aged, about 40%
carbon.

62. Bituminous coal – soft coal formed when
lignite is compacted and altered for
millions of years, about 85% carbon, this
coal is the most commonly mined and used
for a fuel.

63. Sedimentary Rock Features

Features in sedimentary rock that reflect
the sedimentary environment.

Not found in other rock types.

Features:





Stratification
Fossils
Ripple marks & crossbeds
Mud cracks
Nodules, concretions & geodes

64. Rock Stratification (layering) Bryce Canyon,
UT
Photo used with permission from Mike Jarvis, Naperville

65. Ripple marks caused
by wave action on the
sandy bottom of a
shallow bay
Almost identical
ripple marks on
the surface of a
sandstone
millions of years
old.

66. Mud cracks in
drying mud
Mud cracks
preserved on
the bedding
surface of a
shale.

67. Geode
Thunder Egg
Groundwater dissolves hollow spaces in
sedimentary rock, typically limestone, and
mineral material is deposited inside the
hollow with crystal points growing toward the
center.

68. Cross-bedding at Checkerboard Mesa
Zion National Park, UT
Photo used with permission from Mike Jarvis, Naperville
Central HS, Naperville, IL

69. Dinosaur skeleton preserved in
sedimentary rock - China
Photo used with permission from Mike Jarvis, Naperville

70. THE IMPORTANCE OF SEDIMENTARY ROCKS
•
petroleum geology relies on the capacity of sedimentary
rocks to generate deposits of petroleum oils. Coal and oil
shale are found in sedimentary rocks. A large proportion
of the world's uranium energy resources are hosted within
sedimentary successions.

71. Metamorphic Rocks

72. It is metamorphosed

73. Formation of Metamorphic Rock



Changed from one type of rock into
another by heat, pressure, and chemical
processes.
Form deep beneath the earth’s surface.
ALL metamorphic rocks are formed from
existing igneous, sediment or
metamorphic rocks.

74. metamorphic rocks: controlling factors
 • temperature and pressure during metamorphism
 • tectonic forces
 • fluids

75. temperature during metamorphism
• heat from Earth’s deep interior
• all minerals stable over finite temperature range
• higher temperatures than range cause melting
(and therefore generates igneous rocks)
heat is essential
think about mixing flour, yeast, water, salt….
….nothing happens until they have a heat source
and then they make bread

76. pressure during metamorphism
pressure in the Earth acts the same in all directions
pressure is proportional
to depth in the Earth
increases at ~1 kilobar
per 3.3 km
look at example with deep water
pressure increases
with depth
volume decreases
with depth
consequence on cube is squeezing
into smaller cube
--grains pack together-high pressure minerals: more compact and dense

77. tectonic forces - driven by plate motion!
lead to forces that are not equal in all directions (differential stress)
compressive stress (hands squeeze together)
causes flattening at 90° to stress
shearing (hands rubbing together)
causes flattening parallel to stress

78. flattened pebbles in metamorphic rock

79. fluids
• hot water (water vapor) most important
• heat causes unstable minerals to release water
• water reacts with surrounding rocks
and transports dissolved material and ions
time
• metamorphism may take millions of years
• longer times allow new minerals to grow larger
--coarser grained rocks

80. Formation


Minerals may change in size or shape or
separate into parallel bands.
Metamorphic formation happens two
different ways


Contact metamorphism
Regional metamorphism

81. Contact Metamorphism

82. Regional Metamorphism
Regional metamorphism occurs where rocks are
squeezed between two converging lithospheric
plates during mountain building.

83. Classification of Metamorphic Rocks

Rocks can be classified into two different
types based on their texture:


Foliated: which is when the rock grains are
arranged in parallel layers or bands.
Nonfoliated: which is when the rock grains are
arranged randomly.

84. Foliated Rock

85. Nonfoliated Rock

86. foliated (layered) metamorphic rocks
results from differential stress (not equal in all directions)
foliation

87. foliated metamorphic rock: slate

Slate is formed from shale.

88. foliated metamorphic rock: phyllite (higher T, P than slate)

89. foliated metamorphic rock: schist (higher T, P than phyllite)
…new minerals grow -- garnet (large, roundish grains)
garnet

90. foliated metamorphic rock: gneiss (higher T, P than schist)
banding of quartz/feldspar and ferromagnesian minerals

91. The typical transition in mineralology that results from
progressive metamorphism of shale.

92. non-foliated (non-layered) metamorphic rocks
results from pressure: equal in all directions
named on the basis of their composition
marble (CaCO3)

93. The exterior of the Taj Mahal is constructed mainly of the
metamorphic rock marble.

94. non-foliated metamorphic rocks: quartzite
metamorphosed
quartz sandstone

Quartzite is formed from sandstone.

95. non-foliated metamorphic rocks: hornfels
metamorphosed
basalt
Photo credit: R. Weller

96. Diamonds

Diamonds are formed from Coal

99. Rock Cycle

Geologic forces cause rock to constantly
change from one type to another

100. 
The Rock Cycle describes the continually changing structure of rocks.
 Igneous, sedimentary, or metamorphic rock are just temporary stages in
the continuing changes that all rocks undergo.