A mineral is the basic building blocks all rocks.

Different mineral mixes reveal the rocks origin and give the rock its name.

Geologists and Mineralogist, who are scientists who study

minerals and mineral formation, have identified and named

over 6,000 different minerals.

Minerals come in a rainbow of different colors and crystal structures.

A mineral must meet five qualities to be considered a mineral.

A mineral is solid.

A mineral is naturally occurring.

That means it's never man-made

A mineral has an inorganic origin.

that means that the mineral comes

from non-living things.

A mineral has a crystal structure.

The atoms that make it up have a regular repeating pattern.

A mineral has a definite chemical formula.

The atoms that make it up will always be the same

Silica will always be SiO2

and calcite will always be CaCO3

Rocks are made-up of minerals.

Minerals are not rocks.

The most valuable minerals tend to be metal ores,

or minerals that we can extract metals from.

Many minerals contained metallic elements which can be extracted

which can be extracted

Other minerals are useful for their chemical compounds in flavoring our food

Salt is a prime example it comes from mineral halite.

graphite is using a number of products including

the core of pencils.

Still other minerals are prized for their beauty and elegance

Gemstones and jewelry are just a few of these treasures.

Due to the huge number of minerals in the world

Geologists use several different tests to determine

the identity as a mineral.

The first and most basic is color

The problem with color

is that small impurities within the crystal structure

can dramatically change the appearance of a mineral.

In addition several minerals may share the same color.

Green is a very common color among minerals which contained copper.

A small amount of titanium can change colorless diamond blue.

The next test which can be performed

is density.

Density is a measurement

of the ratio of a minerals mass to its volume.

The more mass contained in a given volume

the greater the density.

We calculate density

as a ratio of mass to volume.

First we measure the mass a mineral sample using a balance.

Because mineral samples are usually

unevenly shaped, we can use the water displacement method to determine the

volume of the sample.

The graduated cylinder here has three hundred milliliters of water in it.

When we add the mineral sample to the cylinder,

it now reads 375 milliliters.

The seventy five milliliter increase is the volume

the sample took up.

Density can then be calculated

by dividing the mass by the volume.

Crystal structure is a repeating geometric configuration

having straight edges and flat faces.

The atoms within a mineral are arranged

in an ordered repeating way.

Crystals can be very small

and not always visible to the human eye.

But all minerals

will have a crystal structure.

An eerie calm rolls

across some barren stretch of land.

but deep within the earth something strange

and beautiful is happening.

Within moments, rumblings from below break the silence.

And in a tremendous explosion of

fire and heat

molten lava spews forth

in all directions,

bearing witness to the fury below.

Within the earth's molten liquid rock,

Minute particles called atoms

dance wildly in every direction.

As this molten mass cools,

the movement of atoms slows down,

and similar atoms begin

bonding themselves together in an orderly fashion.

This process is called crystallization.

Which results in the formation of solid minerals.

If conditions are just right, atoms of the same minerals and will continue to

bond together

creating wondrous crystal shapes.

These crystal forms represent an outward expression

of the internal arrangement of atoms.

But what happens when two or more minerals of different types.

crystallized together?

We'd have the birth

of a common rock

The shape and structure at the Crystal reflects the pattern

or arrangement atoms and molecules found within the mineral.

Crystals are divided into six patterns. Ranging from simple cubic

shapes, to complex multi-sided shapes.

Depending on how the atoms within a crystal are arranged, a mineral can have

very different hardness properties.

Hardness is the scratchability of a mineral.

We use the Moh's hardness scale of minerals

to give a numeric value to the hardness of a mineral.

The Moh's scale uses a set of 10 common index minerals

ranging from talc, used in baby and body powder, at 1

to diamonds, the world's hardest known material, at 10.

We use this set have known materials to scratch an unknown sample

and then compare the results against the Moh's hardness scale.

Index mineral 1 does not scratch the sample.

The sample is harder than a 1.

Index mineral 2 does not scratch the sample

So the sample is harder than a 2.

Index minerals 3 does not scratch the sample.

So the sample is harder than a 3. index mineral for

Index mineral 4 does not scratch the sample.

The sample is harder than a 4.

Index mineral 5 does not scratch the sample.

The sample is harder than a 5.

Index mineral 6 does not scratch the sample.

So the sample is harder than a 6.

Index mineral 7 does scratch the sample.

See the little scratch?

That means that the mineral sample is softer than a 7.

Halfway between 6 and 7 is 6.5

The mineral has a hardness of 6.5.

The next test to consider is luster.

Luster is how light reflects off a crystal face.

Luster is divided into two categories

either metallic or non-metallic.

Metallic lusters look like metal non-metallic lester's

Non metallic lusters do not.

Luster- the way light is reflected from the mineral's surface.

Waxy, Metallic

earthy, and vitreous are all words used to describe luster.

Because color can be unreliable,

scientists use a streak test to determine the true color of a mineral.

Minerals can react with the atmosphere and appear very different to their true color

The streak is the color of the powdered mineral.

Streak is usually found by rubbing a mineral sample

against a piece unglazed porcelain.

Minerals harder than the streak plate,

which has a hardness of 7, will not have a streak

because the plate is not hard enough to grind up the mineral sample.

When a mineral breaks it can break in one of two ways:

it can cleave or it can fracture.

Cleavage is a tendency is a mineral to break along flat plains and straight lines

A mineral may have cleavage in only one direction,

such as mica, which breaks off into thin sheets.

There can be two directions of cleavage.

Creating breaks that have two flat surfaces and one jagged surface.

This is a way that feldspars break.

Lastly, you can have three planes of cleavage,

creating cubes or rhombahedrons.

Galena and Halite

both have three planes of cleavage

and break into small cubes when broken.

Look at this mineral sample.

When broken with a hammer, small flat pieces up the sample flake off.

Because these pieces have flat plains and surfaces

the mineral shows cleavage when broken.

If a mineral does not have cleavage, it has fracture.

Fracture occurs when a mental breaks

in an uneven or rough way.

Quartz does not cleave, instead it fractures with a rough and uneven edge.

This specific type of fracture shown by quartz is called concoidal fracture.

fracture

Look at this mineral sample.

When broken with a hammer

uneven and irregular pieces are broken off.

These pieces have no flat plains or surfaces.

instead they're completely irregular.

This mineral shows fracture, not cleavage.

There are several other tests that can help identify a mineral.

Some minerals such as fluorite and some samples of calcite

will fluoresce under ultraviolet light.

Magnetite an iron ore is magnetic, hence its name

Sulfur has a particularly pungent smell and is recognizable

as the smell of matches as well as brimstone.

Many carbonate minerals react to acid by creating carbon dioxide

which fizzes and effervescences on the surface.

Halite, or sodium chloride NaCl,

taste like salt, because it is salt.

However it's not a good idea to lick minerals,

the sample could have been in contact with many hands

and you wouldn't wanna lick all those people.