6.1 Mineral in Earth's Crust

Chapter 6 : Land and its resources

6.1: Minerals in the Earth’s CrustPn. Rohaillah binti Mohd Jabid

SMJK Chong Hwa, KL

What a mineral is?

1. Minerals are natural elements or a compound in the Earth's crust.

2. Mineral can be divide into 2 :i) Natural elementii) Natural Compound

Natural Element1. Natural minerals means they are found uncombined

with another element.

2. Metal Natural elements that are usually found in the

Earth's crust are gold, silver, platinum , mercury and

arsenic

3. Non-metal natural element are carbon and sulphur

5. The table below shows the percentage of

mineral elements found in the Earth's crust :

Element Weight percentage %

Oxygen 46.6

Silicon 27.7

Aluminium 8.1

Iron 5.0

Calcium 3.6

Natrium 2.8

Potassium 2.6

Magnesium 2.1

Titanium 0.4

Hidrogen / Karbon 0.14

1. Natural compound is the mineral that made up more than one element.

2. Natural compound usually will combine with:

i) Oxygen (oxides)

ii)Carbon (Carbonates)

iii)Sulphide (Sulphides)

iv)Silicon (Silicates)

Natural Compound

Natural Compound Mineral Element

Oxide Haematite Iron, oxygen

Cassiterite Tin, Oxygen

Carbonate Calcite Calcium, carbon, oxygen

Malachite Copper, carbon, oxygen

Sulphide Iron pyrite Iron, sulphur

Galena Lead, sulphur

Silicate China clay Aluminium, silicon, oxygen

Calcium silicate Calcium, silicon, oxygen

Properties of minerals

1. Properties of minerals can be determine by their:

-hardness (by scratching)

-solubility (Using water)

-effect of heat

2. Minerals are hard and insoluble in water.

3. Most (i)metal oxides are stable and cannot be broken down by heating.

4. For (ii)metal sulphide, when heating it will breaks down into metal oxide and releases sulphur dioxide gas.

Changes the potassium manganate (VII) solution from

purple to colourless

5. The equation:

Metal sulphide + oxygen ------------> metal oxide + sulphur dioxide

For example:Iron sulphide + oxygen-------------> iron oxide + sulphur dioxide

6. For (iii)metal carbonates, when heating it will breaks down into metal oxide and releases carbon dioxide gas.

Causes limewater to turn cloudy.

7. The equation:

Metal carbonate + oxygen ----------> metal oxide + carbon dioxide

For example:Calcium carbonate + oxygen--------> calcium oxide + carbon dioxide