A Compound is…..

A substance made from two or more different elements that have been chemically combined.

A Mixture, on the other hand, is…

A substance made from two or more different elements that have not been chemically combined, and which can be separated by physical means

A Mineral is a naturally occurring Inorganic Solid with a definite chemical composition and a

crystalline structure.

That means that…

•It can’t be organic in origin

•It can’t be a liquid and..•It has to have a crystal structure

5 Characteristics of minerals are:

1. Inorganic2. Solid3. Occurs Naturally4. Definite Chemical

Composition5. Atoms are arranged in an

orderly pattern

Rocks that have a high percentage of Silicates are light in color, and

are called Felsic rocks.

Rocks that have a low percentage of Silicates are dark

in color, and are called Mafic rocks.

How do Minerals Form???

1. Minerals form in cooling magma chambers

Different types of minerals crystallize at different temperatures

Decreasing temperature

Mineral formation in a Magma ChamberBowen’s Reaction Series

Also the size of the mineral crystals is determined by the rate of cooling of the magma.

-Large crystals form when the magma cools very slowly.

-Small crystals form when the magma cools very quickly.

OlivinePyroxene

Peridotite- Mostly Olivine Gabbro- Pyroxene and Olivine

Gabbro- Pyroxene and Olivine

Pyroxene

2. Metamorphic Minerals:Some minerals occur as the result of Recrystallisation and Reaction within

existing rocks which produces new minerals in response to changes in

and

Pyroxene

3. Some types of minerals form as water containing dissolved ions slowly evaporates.

Salt deposits

A Crystal is….

A regular geometric solid with smooth surfaces called….

Minerals are identified and classified by visual inspection, and

by performing simple tests to determine their physical properties

Color is the most easily observed, but least reliable property of a mineral for identification.

This is because the color of many minerals varies with the kind of impurities in the mineral.

Streak is the color of the powder left on a streak plate when a mineral is rubbed on it.

Streak is much more reliable than color because, although the color of a mineral changes, its streak does not.

Luster is the way in which a mineral shines in the light.

Cleavage is the tendency of a mineral to split in a particular direction.

Fracture is the tendency of a mineral to break in directions other than along crystal faces or cleavage surfaces.

Hardness is the resistance of a mineral to being scratched.

The Mohs Hardness Scale is one of the most effective tool for identifying minerals.