Geology mineralogy

1. “MINERALOGY”
GROUP 5
GEOLOGY FOR CIVIL ENGINEERING

2. Mineralogy
 Minerals are raw materials,, they form a part of the rock, foundation and also
structural base of the civil design.
 Knowledge of mineral properties and its constituents are important for who supervise
the civil works at the civil construction site and it is quite evident that knowledge of
minerals is important for civil engineering professionals.
 Mineralogy is the scientific discipline that is concerned with all aspects of minerals,
including their physical properties, chemical composition, internal crystal structure,
occurence, and distribution in the nature and their origins in terms of physiochemical
conditions of formation.

3. ASPECTS OF MINERALOGY
PHYSICAL
CHEMICAL
ENVIRONMENTAL
ECONOMIC
DESCRIPTIVE
CRYSTALLOGRAPHY

4. “MINERALS
”
 Mineral is naturally occuring inorganic substance which has a
definite chemical composition normally uniform throughtout its
volume.
 In contrast, rocks are collection of one or more minerals.
 Minerals are natural occuring homogeneous solid chemical
substances.
 All of them have very distint chemical composition, highly
ordered atomic structures.
 Mineral by definition, cannot be liquid or gas.
 The atoms is a mineral are arranged in a highly ordered
fashion, called a crystal lattice structure.

5. “CRYSTALLOGRAPHY”
 A mineral specimen, form a single crystal or cluster of
crystal. The requirements are that the mineral has benn free
to grow outwards into the solution or melt from which it
formed.
 The study of this regularity of form and of the internal
structure of the mineral to which it is related.
 The specimen is crystalline even though it is not a crystal.
 The study of the regularity of crsytal forms, including the
values of interfacial angles, shows that all crystals possess
certain elements of symmetry.
ELEMENTS OF SYMMETRY
1. CENTER OF SYMMETRY = All its faces occur in parallel pairs
on opposite side of the crystal.
2. AXIS OF SYMMENTRY = A line through a crystal such that a
complete rotation of 360 degrees about it produces more than one
identical view.
3. PLANE OF SYMMENTRY = Divides the crystal into halves,
each of which is a mirror immage of the other without rotation.

6. “PHYSICAL PROPERTIES OF MINERALS”
1. COLOR
 In mineralogy, color is one of the primary dianostic
properties of natural composition of great importance in
geological prospecting for the identification of minerals.
BASIC OF THE PROPERTY OF COLOR:
1. IDIOCHROMATIC- Self colored.
2. ALLOCHROMATIC- Other colored.
3. PSEUDOCHROMATIC-False colored.
3. HARDNESS
 Measured by the resistance which a smooth surface offers to
abrasion.
 The Mohs scale of mineral hardness is a qualitative ordinal
scale chracterizing scratch resistance of various minerals
though the abiity of harder material to scratch softer
material.
 The hardest mineral is IONSDALEITE, this is up to 58
percent more stress than diamond.
2. STREAK
 Also called powder color, of a mineral is the color of
the powder produces when it is dragged across an un-
weathered surface.
 The minerals streak is said to be white or colorless.
 Streak is particularly important as diagnostic for
opaque and colored materials.
 Streak plate is a piece of unglazed percelian used in
scraping a specimen in performing the streak test.

7. 4.CRYSTALLING STRUCTURE (
INDVIUAL CRYSTALS)
PLATY = broad, flat crystal
TABULAR = Elongate which also flat
PRISMATIC = elongated in one direction
ACICULAT = very long and needle like
FIBROUS = long crystals like fibers
CRYSTALAGGREGATES = amorphous minerals
DENDRITIC = diverges from each other like brances
RENIFORM = kidney shaped
BOTRYOIDAL = like a bunch of grapes
AMYGDALOIDAL = infillinf of holes in lavas
DRUSY = found in lining a cavity
“PHYSICAL PROPERTIES OF MINERALS”
5. CLEAVAGE AND FRACTURE
 Cleavage is the tendency of a crsytal to break along smooth, flat
planes of structual weakness.
 A cleavage plane is always parallel to a crystal face.
 Fracture is the tendency of a mineral to break along the curved
surface with irregular shapes.
 The minerals that undergo fracture do not have weakness. There
are only few to describe the fracture, conchoidal, hackley,
splintery, even, uneven, earthy, or rough.
6. DIAPHANEITY OR TRANSPARENCY
 Diaphaneity of a mineral describe the ability of light to pass
through it.
 Tranparent minerals do not diminish the intensity of light
passing through them.

8. “PHYSICAL PROPERTIES OF MINERALS”
7. TENACITY
 The reaction of a mineral to stress such as crushing,
bending, breaking, or tearing. Certain minerals react
differently to each type of stress.
DIFFERENT FORM OF TENACITY
1. BRITTLE = If a mineral is harmmered and the
result is powder or small crumbs
2. SECTILE = Can be separated with a knife.
3. MALLEABLE = Can be flattened by pounding
with a hammer.
4. DUCTILE = Can be stretched into a wire is
ductile.
5. FLEXIBLE BUT INELASTIC = Mineral can be
bent.
6. FLEXIBLE AND ELASTIC = When flexible and
elastic minerals are bent, they spring back to their
original position
8. MAGNETISM
 When there is an imbalance in the
structural arrangement of the iron ions,
iron is found in two principle ionic states
called ferrous and ferric ions.
MAGNETIC PROPERTIES
FERROMAGNETISM = Strong attraction to
magnetic fields
PARAMAGNETISM = Weak attraction to
magnetic fields
DIAMAGNETISM = Only one mineral,
Bismuth, meaning it is repelled from magnetic
heated.

9. “PHYSICAL PROPERTIES OF MINERALS”
9. LUSTER
 Mineral appears to reflect lights, and how brilliant or dull the
mineral.
USED TO DESCRIBE LUSTER
1. METALLIC= Are opaque and reflective.
2. SUBMETALLIC= That is opaque to nearly opaque and reflects
well.
3. VITREOUS= Acoounts for roughly 70% of all minerals. This
reflective properties similar to glass.
4. ADAMANTINE= Transparent to translucent minerals with a
high refractive index yield.
5. RESINOUS= Luster of manu yellow, dark orange or brown
with moderately high refractive indices.
6. SILKY= The result of a mineral having a fine fibrous
straucture.
7. PEARLY= The inside of a mollusk shell or shirt button.
8. GREASY= Coated with grease.
9. PITCHY= With a tar-like appearance have a pitchy luster.
10. WAXY= Mineral that appears as if it were coated with a layer
wax.
11. DULL= With poor reflective qualities, like unglazed porcelain.
10. ODOR
 Minerals give off a distinctive odor in certain
conditions, when the minerals in heated.
11. TASTE
 Is not the first property someone would
associate with minerals,
 The most commonly “tasted” mineral is halite or
rock salt, but there are several other minerals
that have a distinctive taste.
12. SPECIFIC GRAVITY
 Also known as SG, a measurement that
determines the density of minerals. Two
minerals may be the same size, but their
weight may be very different.
 OSMIUM, the densest naturally occuring
element on the earth, which belongs to the
precious platinum group of metals.

10. ROCK FORMING MINERALS
 These are any mineral that forms igneous, sedimentary, or metamorphic
rocks and that typically, or solely, forms as an intimate part of rock making
processes.
 Those minerals that have a limited move of occurrence or are formed by
more unusual processes, such as the ores of metals, vien minerals, and
civity fillings.
ENGINEERING SIGNIFICANCE OF ROCKS
 It is important to know the properties of rocks precisely to enable
them to consider different rocks for any required purpose.
 Properties of civil engineering importance such as their strength,
durability, and appearance of rocks can be assessed only with the
knowledge of the minerals that form rocks.

11. THANK YOU!