MINERALS
EARTH AND LIFE SCIENCE

INTRODUCTORY QUESTION:
◦Do you know what is a mineral?
◦What is/are the thing/s you associate with a mineral?
◦Do you know where they came from?

MINERALS
◦It is a naturally-occurring chemical compound that occurs naturally
in its pure form
◦It is a homogenous solid and has a stable temperature of at least
25˚C
◦It has a definite chemical composition. Thus, it has definite
chemical constituents
◦It has an ordered crystalline structure

WHERE DOES MINERALS COME FROM?
◦It comes from the cooled and crystallized version of an igneous
rock that consists of various minerals
◦Mineral deposits can only be extracted where they can be found

PROPERTIES OF
MINERALS

1. Color
◦It is usually determined either by the mineral’s composition or its
crystalline structure
◦It is usually caused by electromagnetic radiation interacting with the
electrons

1. Color
◦Idiochromatic Minerals
◦It is the so-called “self-colored” minerals due to its composition
Examples: Azurite (blue) and Malachite (Green)

1. Color
◦Allochromatic Minerals
◦It is the so-called “other-colored” minerals due to traces of its
impurity or caused by the defects of its structure
◦The color is an unpredictable property

2. Streak
◦It is the color of the mineral in powdered form. The difference of
their colors resulted from the presence of smooth surfaces of
compact crystals that sometimes reflect light differently in
comparison to powdered mass
◦Most of the time, the powdered color is also the color of its original
form

3. Luster
◦It is the behaviour of light as it is reflected by the surface of a
mineral
◦Metallic Minerals – it reflects light similar to a polished metals and
a good conductor of heat and electricity
◦Non-Metallic Minerals – it is characterized by a not shiny surface
and can yield new products while undergoing melting

4. Diaphaneity
◦It is the ability of the mineral to allow light pass through it
◦It may depend on the mineral’s thickness

5. Hardness
◦It is the resistance of a mineral from scratching
◦In determining hardness, it is tested by scratching the surfaced with
a measurable amount of force

Friedrich Moh’s Scale of Mineral Hardness

6. Cleavage
◦It is the tendency of a mineral to break along particular directions
◦When force is applied, it tends to separation on regions where the
bonding is relatively weaker
◦It can be seen as a series of parallel lines marking the planar
surface

7. Magnetism
◦It is the tendency of a mineral to be attracted by a magnet that can
be caused by the movement of electrons in their crystalline
structure
◦It is mostly used in identify whether one is a mineral or not