The document discusses minerals, defining them as naturally occurring inorganic solids with a definite crystalline structure and chemical composition. There are over 3,500 known minerals that make up Earth's crust. The majority of rocks are formed from combinations of just 20 minerals. Minerals have several physical properties that can be used to identify them, including color, luster, streak (powder color), and hardness on the Mohs scale. Silicates and nonsilicates are the two main groups of rock-forming minerals.

1. I. Minerals
Earth and Space Science

2. A. Definition – four part definition
 Naturally occurring
 Inorganic substance (non-living)
 Crystalline solid
 Definite chemical composition

3. • There are substances that meet 3 of the 4
criteria, and are called mineralloids
 Example: Opal – does not have an orderly
arrangement of atoms

4. B. How many minerals are there?
- 3500 known minerals in the Earth’s crust
- Minerals combine to form all rocks on Earth
 Rock type depends on mineral composition
- 20 minerals combine to form 95% of all rocks
on Earth.

5. What do all minerals have in common?
• For a substance to be a mineral it must have these 5
characteristics:
1. Formed by natural processes on or inside Earth- no help from
humans
2. Is inorganic- was never alive. For example, although coal was
formed naturally in earth’s crust it came from plants and is
therefore, not a mineral
3. Is a solid, with definite volume and shape. Liquids cannot be
minerals!
4. Minerals always contains certain elements that give it a unique
chemical composition (makeup). Some minerals are compounds
which are made up of more than one element.

6. The Structure of Minerals
• The Structure of Minerals Recall that minerals have definite crystalline
form and that the shape reflects the internal arrangement of atoms or
ions.
• Compare the shape of the quartz crystals to the shape of the calcite
crystals.
• Well-formed quartz crystals are long and typically have distinctly
pointed ends. Well-formed calcite crystals are somewhat diamond
shaped and have sets of parallel sides.

7. The Structure of Minerals
• Have a crystalline shape- the particles of a
mineral line up in a pattern that repeats forming
a crystal.
• Crystal- solid with atoms arranged in an orderly,
repeating pattern

8. 5. Crystal shape / External Crystal
Form / Crystal Systems
 a set of faces that have a definite
geometric relationship to each other

9. The two main families of rock-forming minerals are:
• The silicates
• The nonsilicates.
A silicate is a member of the mineral group that has silicon and oxygen in its crystal
structure. Quartz, with the chemical composition of is a silicate mineral. Feldspar is
the most common silicate mineral in Earth’s crust.

11. Non-Silicates
• Silicates make up the vast majority of the minerals on the earth.
• Still, that doesn't mean that the rest are unimportant.
• The only requirement for being a non-silicate is that the molecular structure
• Still, that leaves quite a bit of potential possibility for the resulting non-

13. C. Physical Properties
- All minerals have physical properties that can
be used to define, describe, and identify them
as unique minerals.

14. • 1. Color – every mineral is some color and
some are found in multiple colors
•  could be very helpful and distinctive, or
could be very ambiguous

15. 2. Luster – the manner in which a mineral
reflects light
 Glassy – reflects light like a piece of glass does
 Metallic – reflects light like a piece of metal does

17. 3. Streak – the color of the pulverized powder of
a mineral

18. The color could be
different from the
crystal’s color, and
is always distinctive

19. • 4. Hardness – the scratchability of a mineral,
or a mineral’s durability
Uses the Moh’s Hardness scale with a rating
system of 1-10
*1 = very soft
*10 = hardest
substance
known to man
*A streak plate has a
hardness of 7

20. Moh’s Hardness Scale

21. What are metallic minerals?
• Are minerals containing one or more metals.
• These usually occur as mineral deposits.
• Are a great heat and electricity conductor, such as
iron, copper, silver, bauxite, manganese, etc.

22. What are nonmetallic
minerals?
Consist of:
• quarries of stone and clay and sand pits;
• mineral deposits with chemical and fertilizer;
• salt deposits;
• quartz deposits, gypsum, natural gemstones, asphalt and bitumen, peat
and other non-metallic minerals other than coal and oil.