PTPA to the owner

2. WhatisaMineral?
 Naturally-formed solid substance with a
crystal structure

3. What do all minerals have in common?
All:
Are formed by natural processes.
Are NOT alive and NEVER were alive
Have a definite volume and shape
Are elements or compounds with a unique
chemical makeup
Are made up of particles that are arranged in
a pattern that is repeated over and over
(called a CRYSTAL)

4. 1.What element are diamonds made from?
2. What do all crystals have in common?

5. Groups ofMinerals
 Minerals are grouped by the elements they
are made of.
Beryl (Emerald) Calcite
Amethyst

6. Min e r a l
Gr o u p
Silicates
Ch a r a c t e r i
 Containstics
oxygen & silica
 The most
abundant group
of minerals
Ex a m p l e s
Quartz, mica
MICA Quartz

7. Mineral
Group
Non-Silicates
Silver
Characterics
Include some of
the most
important
minerals
Ex a m p l e s
iron, copper,
gold, silver,
diamonds, rubies
Copper
Diamond
Gold Ruby Iron

8. Mineral
Carbonat es
G roup
Characterics
Carbon oxygen
and a positive
ion, such as
calcium
Examples
Calcite (CaCO3)
Calcite with Duftite inclusions

9. Mineral
OxidesGroup
Ch a r a c t e r i
Metallc ion
and oxygen
Ex a m p l e s
Hematite
(Fe2)O3

10. Min e r a l
SulfidesGroup
Ch a r a c t e r i
Sulfursticands a
metallic ion
Ex a m p l e s
Galena (PbS)

11. Min e r a l
SulfatesGroup
Ch a r a c t e r i

Metallicsticion,s
Sulfur & oxygen
Ex a m p l e s
Barite (BaSO4)
Barite on Calcite
BaSo4 / CaCO3
Barite
BaSo4

12. Min e r a l
NativeGroup
Elements
Ch a r a c t e r i
Singlest ics
elements
Ex a m p l e s
Gold (Au),
Diamond (C),
Silver (Ag)

13. How do minerals form?
 1) Cooling of magma (hot, liquid rock and
minerals inside the earth (from the
mantle))
 Fast Cooling = No Crystals (mineraloids)
 Medium Cooling = SMALL crystals
 Slow Cooling = LARGE crystals

14. How do minerals form?
2) Elements dissolved in liquids (usually
water) will reform into crystals as the
water evaporates and the dissolved
elements recrystalize.

15. Physical Properties of Minerals
(can be used to identify the mineral)
Color
 Can be misleading
 Can vary with the type of impurities

16. Physical Properties of Minerals
(can be used to identify the mineral)
Luster
 Surface reflection
 metallic = shiny like
metal
 non-metallic = dull,
non-shiny surface
Pyrite has a metallic luster
Calcite has a non-metallic luster

17. Physical Properties of Minerals
(can be used to identify the mineral)
Streak
 The color of the powdered
form of the mineral
 The color of the streak can
be different than the mineral
 Minerals must be softer
than the streak plate

18. S t r e a k … c a n h e l p id e n t if y
q u a r t z
Their colors may vary (remember, color Bad!)
http://www.childrensmuseum.org/geomysteries/cube/b3.html

19. Physical Properties of Minerals
(can be used to identify the mineral)
Hardness
 How easily a mineral scratches
materials
 Mohs Hardness Scale
 Scale from 1 (softest) to 10 (hardest)
 Test by seeing if the mineral can scratch
different objects (like human fingernail,
copper, penny, glass, steel file)

21. Physical Properties of Minerals
(can be used to identify the mineral)
Cleavage & Fracture
 The way the mineral breaks
 Cleavage—minerals break along smooth,
flat surfaces and
every fragment has the same
general shape
 Fracture—minerals that break
at random with rough or
jagged edges

23. Cl e a v a g e o r Fr a c t u r
e ?
1
4
2
3

24. Physical Properties of Minerals
(can be used to identify the mineral)
Other Properties
 Specific gravity (*excellent clue to
mineral’s identity)
 Attraction to magnets
 Bending of light
 Reaction with hydrochloric acid
 Smell & taste

25. What is a gem?
 A Mineral OR Rock that has value
 Rare !
 Sometimes polishing or cutting will add
value