How can we identify different minerals?. At the lab tables, decide upon 5 ways to separate minerals into groups with your partner Use the white board.

How can we identify different minerals?

• At the lab tables, decide upon 5 ways to separate minerals into groups with your partner

• Use the white board to share this with your peers!

How would you group minerals?

Properties used to Identify Minerals

• Luster Color• Streak Hardness • Cleavage Feel• Taste Magnetic• Acids

GEODE CD-ROM

Main Menu

1. Earth Materials

3. Properties used to Identify Minerals

More properties to I.D. mineralspage 107 in your book

• Fluorescent• double refraction• Odor• Specific gravity• Radioactive• Solubility in water• Crystal shape

In each Mineral I.D. Lab bag:

1 Hand lens 1 yellow

1 Penny 2 clear

1 Glass plate 2 pink

2 Streak plates 1 dark red

1 magnet 1 flat

1 Nail 1 gold

8 minerals

Physical Properties of Minerals

• Color: light or dark, yellow, gold, pink….

• Luster: – metallic, – Non-metallic: dull, glassy,

vitreous, pearly, adamantine

Light: transparent, opaque, translucent,

double refraction,

Streak• The color of the mineral in its powdered form.• Rubbing the mineral on a streak plate.• Streak is more reliable than color: • Streak is a consistent property of a mineral.• Metallic minerals generally have a dark streak,

– Non-metallic mineral do not

Two different colored forms of the SAME mineral: SAME colored streak

Mohs scale of hardness

Hardness

• Relative scale: comparing the hardness of a mineral to a known object.

• 1-10 • Diamond being the

hardest 10• Talc is the softest 1

Describe a test you can do to identify a mineral.

• Fracture

Quartz (glass) fractures and

shatters into irregular-shaped pieces with

no flat planes

• Cleavage: the tendency of a mineral to break along flat planes of weak bonding

Halite will cleave into many smaller pieces each with 3 planes at 90°

Three examples of perfect cleavage –3 flat planes (sides)

fluorite, halite, and calcite

Name ColorLuster

LightInteraction

Streak Hard-ness

Cleavage Smell Sol.water

Sol.acid

1YellowDull

Opaque Yellow 1-2 none RottenEgg!

IS IS

2 Gold, metallic,shiny

opaque black 6 none none IS SS?

3whitePearly, flat

Transparenttranslucent

none 2-3 Perfect!1 direction peels

none IS IS

4Clearshiny

TransparentDoublerefraction

Nonewhite

3 perfect none IS YES!FIZZ

5Clear, whiteShiny, Tastes salty

translucent none 2-2.5 Perfect!3 direction90° angle

none Yes!dis-solves

IS

6Dark red-browndull

opaque Red-brown

3-4 none None orearthy

IS SS

7Salmon pink opaque none 6 Good

2 direction

none IS IS

8Pink, clearglassy

translucent none 7 Nonefracturesconcoidal

none IS IS

sulfur

Pyrite

Mica(Muscovite)

calcite

Halite(Salt)

hematite

feldspar

Quartz

Mineral Flow Chartin your notebooks copy the chart below

• Color? dark or light _______________• Luster? Metallic or non-metallic ________• Streak? Black, brown or reddish________• Harder than glass? __________________• Cleavage? Yes, no cleavage, 1,2,3,4 planes • Solubility in water? ______• In acid?_______• Mineral Name _____________

Quiz time

• What characteristics do all minerals share?

• Where do minerals come from?

• Name and describe at least three properties that we can use to distinguish minerals.

Which has a higher specific gravity? Metals or non-metals?

Determining the Specific Gravity of a Mineral

1. Get out a piece of notebook paper.

2. Title: SpG & Mineral I.D. (pg. 112-113)

3. Copy Data Table 1 on page 112.

5. Copy the formula on pg. 113

6. Collect the data using a balance

7. Use the table on pg. 113 to Identify the mineral

8. Answer questions #3-8 on page 113

PracticeCalculate the Specific Gravity of the mineral

using the mass measurements.

Mass in air: 15.0 g

Mass in water -12.0 g

SpG =

What mineral is this?

3 g

Mass in airLoss of mass

15.0 g 3.0 g

= 5.0