Minerals are naturally occurring chemical compounds that form in pure crystalline structures within the Earth. They originate as igneous rocks cool and crystallize below the Earth's surface. Minerals have distinct chemical compositions and properties including color, streak, luster, hardness, cleavage, diaphaneity, and magnetism. These properties are determined by a mineral's composition and crystalline structure. Color, for example, is usually caused by electromagnetic radiation interacting with a mineral's electrons. Hardness refers to a mineral's resistance to scratching and is measured using the Mohs scale. Cleavage describes a mineral's tendency to break along planes of weaker atomic bonding.

1. MINERALS
EARTH AND LIFE SCIENCE

2. 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?

3. 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

4. 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

5. PROPERTIES OF
MINERALS

6. 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

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

8. 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

9. 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

10. 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

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

12. 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

13. Friedrich Moh’s Scale of Mineral Hardness

14. 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

15. 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