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How Minerals Form

Dec 4th 2012

+Aim & Learning Target

AIM: What are Minerals? How do minerals form?

Learning Target: I can identify and describe as mineral and give a basic

explanation of how they are formed.

Agenda Do Now Mini Lesson Practice

+Do NOW

How are minerals different from rocks?

How to you think we classify minerals?

What are some common minerals?

+What is a mineral?

Take a minute to brainstorm...

+Definition of a Mineral:

A mineral is a naturally occurring, inorganic solid, with a definite chemical composition, and an ordered atomic arrangement.

+Breaking Down the Definition: Minerals are naturally occurring

They are not made by humans

Minerals are inorganic They have never been alive and are not made up from

plants or animals

Minerals are solids They are not liquids (like water), or gases (like the air

around you)

Minerals have a definite chemical composition Each one is made of a particular mix of elements

Minerals have an ordered atomic arrangement The elements that make up each mineral are arranged in a

particular way

+How do you think minerals form?

Take a minute to brainstorm...

+How minerals form?

Four major processes by which minerals formCrystallization from magmaPrecipitationChanges in pressure and temperatureFormation from hydrothermal

solutions

+Crystallization from magma

Magma is molten rock deep in the earth

As magma cools, elements combine to form minerals

The first ones to form contain iron, calcium, magnesium

Later, sodium, potassium and aluminum minerals form

Examples: Feldspar Quartz muscovite

+Precipitation

When water evaporates, it leaves behind the minerals the are dissolved in it.

Examples: Limestone cave Halite calcite

+Pressure and Temperature

Pressure Minerals can recrystallize

Temperature When temperature changes some minerals become

unstable rearrange structure to become stable.

Examples Talc muscovite

+Hydrothermal Solutions

Hydrothermal solutions are very hot mixture of water and dissolved substance (btw 100 and 300 ˚C)

When in contact with other minerals a chemical reaction forms new minerals.

Examples: Bornite chalcopyrite

+Are diamonds the same as everyone else?

Carbon that makes up diamonds comes from the melting of preexisting rocks in the Earth’s upper mantle

Temp changes in upper mantle forces carbon to go deeper.

When temperature cools, diamond deposits.

Pressure also has to be correct.