Minerals are any naturally occurring inorganic solid that possesses an orderly crystalline structure and a definite chemical composition that allows for some variation. Within this presentation, we shall be discussing how one may be able to identify rocks based on their differing properties. Physical properties which alludes to its color, streak, hardness and many more characteristics shall be used identify a myriad of rocks. Some minerals are chemical compounds having compositions that can be expressed by a chemical formula. This occurs because certain elements can substitute for others of similar size without changing the mineral’s internal structure. Within this presentation we shall be getting a deeper dive within identifying rocks and what-not

1. PHYSICAL AND CHEMICAL
PROPERTIES OF ROCKS

2. What are your basis in identifying
the minerals?

3. What are your basis in identifying the minerals?
Most minerals can be
characterized and classified by
their unique physical
properties: hardness, luster, color,
streak, cleavage and fracture.

4. What are the properties/characteristics of
minerals evident on the pictures above?

5. Streak Luster Crystal Habit
Hardness Color

6. Why do minerals
have different
properties?

7. Minerals can be identified by
their physical characteristics
that is related to their chemical
composition and bonding which
is vital for mineral
identification.

8. MOST ESSENTIAL LEARNING COMPETENCY (MELC):
• Identify common rock-forming minerals using their physical
and chemical properties (S11/12ES-Ia-9)
OBJECTIVES:
At the end of the lesson, students must be able to:
• Identify some common rock-forming minerals
• Classify minerals based on their physical and chemical
properties

9. MINERAL
▷ any naturally occurring inorganic solid
that possesses an orderly crystalline
structure and a definite chemical
composition that allows for some
variation.

10. Characteristics:
NATURALLY OCCURRING. Minerals
form through natural geologic processes.
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GENERALLY INORGANIC. Inorganic
crystalline solids that are found naturally
in the ground are considered minerals.
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11. Characteristics:
SOLID SUBSTANCE. Only solid
crystalline substances are considered
minerals. Ice (frozen water) fits this
criterion and is considered a mineral.
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12. Characteristics: ORDERLY
CRYSTALLINE
STRUCTURE.
Minerals are
crystalline
substances, which
means their atoms
(ions) are arranged
in an orderly,
repetitive manner
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https://geology.com/minerals/what-is-a-mineral.shtml

13. Characteristics:
DEFINITE CHEMICAL
COMPOSITION FOR SOME
VARIATION.Minerals are chemical
compounds having compositions that can be
expressed by a chemical formula. This occurs
because certain elements can substitute for
others of similar size without changing the
mineral’s internal structure.
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14. Atoms of the naturally occurring elements are the basic building
blocks of Earth’s minerals. Most elements join with atoms of other
elements to form chemical compounds.
Therefore, most minerals are chemical compounds composed of atoms of
two or more elements. These include the minerals quartz (SiO2),
halite (NaCl), and calcite (CaCO3).
However, a few minerals, such as native copper, diamonds, sulfur, and
gold, are made entirely of atoms of only one element.

15. PHYSICAL PROPERTIES
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16. COLORS
The same mineral
can have many
different colors. It
can also change
colors when the react
with air or water.
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Malachite (J.J. Harrison, 2009)
Sulfur (Hemmerlein, 2005)
Source: Earth and Life Science Quipper Guide

17. COLORS
The same mineral
can have many
different colors. It
can also change
colors when the react
with air or water.
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18. STREAK
The color of the
powdered form of a
mineral. It is
observed by rubbing
the mineral across a
streak plate.
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A specimen of pyrite (left) produced a black
streak while rhodochrosite (right) produced a
white streak (Raike, 2010)

19. LUSTER
the appearance of a mineral’s surface
and is dependent on how it reflects light
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From left to right: Sphalerite (resinous); Feldspar (dull); Quartz (vitreous) and; Pyrite (metallic)
Image Credits: Rob Lavinsky, 2010; J.J. Harrison, 2009; C. Millan, 2009

20. Remember!
▷ A mineral has a metallic luster if it has the same
appearance as a polished metal.
▷ Vitreous luster occurs if it has the same sheen as a
glass.
▷ Resinous luster has the same sheen as amber or
resin.
▷ A mineral is said to acquire a dull luster it has a
plain-looking sheen and is the opposite of metallic
and submetallic.

21. CRYSTAL HABIT
The characteristic shape in which a mineral grows and is a
projection of the mineral’s crystal structure. Some common
habits are columnar, tabular, prismatic, and botryoidal.
Hematite
botryoidal
Ebaite
prismatic
Barite
tabular
Quartz
columnar
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22. CLEAVAGE
The tendency of some
minerals to break along
flat surfaces. These
surfaces are where the
atomic bonding is at its
weakest. Minerals may
have up to six cleavage
directions.
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24. FRACTURE
The pattern in which
the mineral breaks aside
from its planes of
cleavage. This happens
when the atomic bonds
are of equal strength.
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Irregular Fracture
Conchoidal Fracture

25. HARDNESS
The resistance of the minerals to scratching.
It is measured by scratching the mineral with
another object of known hardness.
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26. Mohs Scale
(Relative Hardness)
The Mohs scale is a
relative ranking, and it
does not imply that
mineral number 2, gypsum,
is twice as hard as mineral
1, talc. In fact, gypsum is
only slightly harder than
talc

27. CHEMICAL PROPERTIES

28. SOLUBILITY
The ability of a substance to dissolve in a solvent
at a specified temperature.
Example: Biotite, a mineral commonly found in
igneous rocks, is soluble in both acid and base
solutions. The dissolution releases the loosely-
bound potassium ions in the mineral.
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29. MELTING POINT
▷ refers to the temperature at which solid
turns into liquid. Minerals composed of
atoms that are tightly bonded within
the crystal structure have high melting
points.
For example, quartz melts above 1670° C.
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30. A piece of mineral crystal which, in
cut and polished form, is used to
make jewelry or other adornments.
gemstones
• Precious stones were the Big Four – Diamonds,
Emeralds, Rubies and Sapphires.
• Semi-precious stones were everything else.

31. Most precious stones are
given names that differ
from their parent
mineral.
For example:
•Sapphire - tiny amounts of
titanium and iron in
corundum produce the most
prized blue sapphire.
•Ruby - mineral corundum
contains a sufficient
quantity of chromium, it
exhibits a brilliant red
color.