Transcript What is a Mineral?

What is a Mineral?

Naturally-formed solid substance with a
crystal structure
Pyromorphite
What do all minerals have in
common?
All:
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3.
4.

Are formed by natural processes.
Have a definite volume and shape (it is a SOLID)
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)
Are not alive and never were!
An element is made up of one specific
type of atom.
 Examples:
Gold is made up of only gold atoms.

Silver is made up of only silver atoms.
1.What element are diamonds made from?
2. What do all crystals have in common?
Groups of Minerals

Minerals are grouped by the elements
they are made of.
Beryl (Emerald)
Calcite
Amethyst
Mineral Group
Characteristics
Examples
Contain
Silicates
silica Quartz, mica
(oxygen and
silicon)
The most
abundant group
of minerals
MICA
Quartz
Mineral Group
Characteristics
Make
Non-Silicates
Silver
up only
5% of the
Earth’s crust
Include some
of the most
important
minerals
Examples
iron, copper,
gold, silver,
diamonds,
rubies
Copper
Diamond
Gold
Ruby
Iron
Mineral Group
Carbonates
Characteristics
Second
most
common rockforming
minerals.
Examples
Calcite (CaCO3)
Calcite with Duftite inclusions
Mineral Group
Oxides
Characteristics
Contains minerals
from which most
metals are refined
(ex. tin and copper).
An oxide usually
consists from of an
element, usually metal
combined with oxygen.
Are not as common as
rock forming minerals.

Examples
Hematite
(Fe2)O3
Mineral Group
Sulfides
Characteristics
Sulfur
and a
metallic ion
Examples
Galena (PbS)
Mineral Group
Sulfates
Barite on Calcite
BaSo4 / CaCO3
Characteristics
Metallic
Sulfur &
oxygen
ion,
Barite
BaSo4
Examples
Barite (BaSO4)
Mineral Group
Native
Elements
Characteristics
Single
elements
Examples
Gold (Au),
Diamond (C),
Silver (Ag)
How do minerals form?

1) Cooling of magma (hot, liquid rock and
minerals inside the earth (from the
mantle))
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Fast Cooling = No Crystals (mineraloids)
Medium Cooling = small crystals
Slow Cooling = large crystals
How do minerals form?

2) Elements dissolved in liquids (usually
water)
Physical Properties of Minerals
(can be used to identify the mineral)
Color
 Can be misleading
 Can vary with the type of impurities
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
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
Streak…can help identify quartz
http://www.childrensmuseum.org/geomysteries/cube/b3.html
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)

Physical Properties of Minerals
(can be used to identify the mineral)
Cleavage & Fracture
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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
Cleavage or Fracture?
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4.
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3.
Physical Properties of Minerals
(can be used to identify the mineral)
Other Properties
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Specific gravity (*excellent clue to
mineral’s identity) http://www.childrensmuseum.org/geomysteries/cube/b4.html
Attraction to magnets
Bending of light
Reaction with hydrochloric acid
Smell & taste
Watch Classifying Minerals Clip