Mineral Properties Each and every mineral has certain mineral properties. The properties of each mineral depends on the following; 1) The type of elements.

Mineral PropertiesEach and every mineral has certain mineral properties. The properties of each mineral depends on the following;

1) The type of elements present

2) The arrangement of atoms

3) The strength of bonding

Reference:

Pages 40 - 44

The following are a list of physical properties that each mineral displays;

1) Specific Gravity 8) Color

2) Hardness 9) Taste

3) Streak 10) Feel

4) Cleavage 11) Magnetism

5) Fracture 12) Acid Test

6) Luster 13) Fluorescence

7) Crystal Shape (Form)

Mineral Properties

1) Specific Gravityis the mass of a mineral compared to that of an equal volume of water

weigh the specimen in air and record the weight.

1)

To determine specific gravity you need to carry out the following three steps:

1) Specific Gravityis the mass of a mineral compared to that of an equal volume of water

To determine specific gravity you need to carry out the following three steps:

weigh the specimen submerged in water and record the weight.

2)

1) Specific Gravity

Specific Gravity = weight in air . weight in air - weight in water

calculate specific gravity (S.G.) using the following formula.

3)

To determine specific gravity you need to carry out the following three steps:

Specific Gravity = DensityNote: (In Reference to Core Lab #4)

Because pure water at 4C has a density of 1 g/cm3, the specific gravity is equal to its density. Thus; Specific gravity = Density.

Density = Mass(mineral) Volume(mineral)

To determine Density you need to:

1) Use a scale to measure the mass of the mineral sample.

2) Find the volume of the mineral sample. (water displacement)

3) Calculate density (which equals specific gravity).

= Specific Gravity

Specific Gravity = DensityGiven: 1mL = 1cm3 = 1g, we know the weight of an equal volume of water in grams. We can then use the following formula to calculate Specific Gravity:

CalculationS.G. = W(mineral)

W(water)

2) HardnessThe resistance of a mineral to scratching. Hardness is expressed in terms of Moh’s Hardness Scale which ranks relative hardness from 1 – 10.

You could use a rhyme to remember the hardness scale:

Tonight Gypsies Come From Africa

On Quads To Catch Dinosaurs

2) Hardness

If the object scratches the mineral then it is harder than the mineral.

The following objects can be used when trying to determine the hardness of different minerals.

2) Hardness

If the object scratches the mineral then it is harder than the mineral.

The following objects can be used when trying to determine the hardness of different minerals.

Nail, hardness of 4.5 scratches a mineral.

2) Hardness

If the object scratches the mineral then it is harder than the mineral.

The following objects can be used when trying to determine the hardness of different minerals.

3) Streak The true color of the mineral in its powdered form.

To find the streak of a mineral, you perform a streak test. To do this you scratch a mineral across an unglazed porcelain tile and the powder streak left on the tile is the true color of the mineral.

4) CleavageThe tendency of some minerals to break along smooth, flat, parallel surfaces.

Cleavage directions are determined by atomic structure and strength of bonding.

4) CleavageThe tendency of some minerals to break along smooth, flat, parallel surfaces.

Cleavage directions are determined by atomic structure and strength of bonding.

Cleavage follows areas of weak bonding.

Cleavage Plane Directions

Cleavage in one direction (Basal Cleavage). Example: Mica displays this type of cleavage.

Minerals show cleavage in many different directions, but most common are in planes of one, two, and three directions.

Cleavage Plane DirectionsCleavage in two directions. Example: Orthoclase feldspar displays this type of cleavage.

Cleavage Plane DirectionsCleavage in three directions. Example: Halite displays this type of cleavage.

5) FractureA mineral that do not have any cleavage planes is said to break by “Fracture". Example is glass or the mineral quartz which is said to have Conchoidal Fracture.

5) FractureAnother example of a mineral that fractures is Asbestos. This mineral displays a Fibrous Fracture.

6) Luster

Most minerals can be described as;

1. Metallic

2. Non-Metallic

The appearance of the mineral in reflected light.

A) Glassy

B) Greasy

C) Earthy or Dull

D) Pearly

Metallic Luster

Most minerals can be described as;

1. Metallic

Non-metallic Glassy Luster

Most minerals can be described as;

2. Non-Metallic

A) Glassy

Non-metallic Greasy Luster

Most minerals can be described as;

2. Non-Metallic

B) Greasy

Non-metallic Earthy (Dull) Luster

Most minerals can be described as;

2. Non-Metallic

C) Earthy . or Dull

Non-metallic Pearly Luster

Most minerals can be described as;

2. Non-Metallic

D) Pearly

7) Crystal Shape (Form)

Most;

The.

A)

B)

C)

D)

8) Color The actual color of the mineral that you see.

This property is less distinctive. (not as reliable as the others) WHY?

Two reasons:

1) Different minerals can have the same color.

Halite

Calcite

8) Color

2) Some minerals may have impurities, which cause a single mineral to have different colors.

Other Properties

These physical properties can be helpful to identify minerals that are similar:

10) Feel - what the mineral feels like. Ex. Graphite - greasy

9) Taste - what the actual mineral taste like. Ex. Halite (rock salt) taste salty.

Other Properties

These physical properties can be helpful to identify minerals that are similar:

12) Acid Test - drop acid on the sample to see if the mineral reacts (fizzes). Used to test the Carbonate group. Ex. Calcite (Limestone)

11) Magnetism - if a mineral is magnetic

or not. Ex. Magnetite (Loadstone).

Other Properties

13) Fluorescence – is the emission of light by a substance that has absorbed light. Fluorescent minerals emit visible light when exposed to ultraviolet light.

Example: