Minerals

What is a mineral? Mineral is a naturally occurring solid composed of several different elements. Most rocks are aggregates composed of two or more minerals. Each mineral has its own unique characteristics. A mineral is the same all the way through.

Mineral is a naturally occurring solid composed of several different elements.

Most rocks are aggregates composed of two or more minerals.

Each mineral has its own unique characteristics.

A mineral is the same all the way through.

What makes up a mineral? Different minerals are made up of different elements. The elements include: silicon oxygen iron sodium chlorine calcium carbon hydrogen aluminum -Si-O-Fe- -Na-Cl-Ca- -C-H-Al-

Different minerals are made up of different elements.

The elements include:

silicon

oxygen

iron

sodium

chlorine

calcium

carbon

hydrogen

aluminum

What are the unique properties of minerals? Each mineral has unique properties. Crystal Forms Luster Hardness Streak Acid Reaction Fluorescence

Each mineral has unique properties.

Crystal Forms

Luster

Hardness

Streak

Acid Reaction

Fluorescence

Crystals Crystals are structures made up of a regular repeated pattern of connected atoms or molecules. There are many different forms of crystal. Cubes, spheres, pyramids, spikes, and some are even 12 sided (like a die) Each mineral has a specific crystal form.

Crystals are structures made up of a regular repeated pattern of connected atoms or molecules.

There are many different forms of crystal.

Cubes, spheres, pyramids, spikes, and some are even 12 sided (like a die)

Each mineral has a specific crystal form.

Luster Luster is the quality or appearance of light reflected. There is metallic luster and nonmetallic luster. Metallic luster: Reflects light like metal. Silver and gold have metallic luster. Nonmetallic luster: Includes silky, glassy, pearly, and dull. Quartz has nonmetallic luster.

Luster is the quality or appearance of light reflected.

There is metallic luster and nonmetallic luster.

Metallic luster:

Reflects light like metal.

Silver and gold have metallic luster.

Nonmetallic luster:

Includes silky, glassy, pearly, and dull.

Quartz has nonmetallic luster.

Luster

Hardness Hardness is the resistance to scratching or abrasion. This is the most useful characteristic of minerals. Each mineral has a specific hardness. There is a scale called “Mohs Scale”. It lists ten minerals in order of their hardness.

Hardness is the resistance to scratching or abrasion.

This is the most useful characteristic of minerals.

Each mineral has a specific hardness.

There is a scale called “Mohs Scale”.

It lists ten minerals in order of their hardness.

Hardness Mohs scale consists of ten minerals that you can use as a reference. Talc is the softest and diamond is the hardest. Talc has a hardness of 1, diamond has a hardness of 10.

Mohs scale consists of ten minerals that you can use as a reference.

Talc is the softest and diamond is the hardest.

Talc has a hardness of 1, diamond has a hardness of 10.

Mohs Hardness Scale 10 Corundum Topaz Quartz Feldspar Apatite Fluorite Calcite Gypsum Talc Diamond 9 8 7 6 5 4 3 2 1

Mohs Hardness Scale To use the hardness scale, try to scratch the surface of an unknown sample with a mineral or substance from the hardness scale (these are known samples). If the unknown sample cannot be scratched by feldspar (6) but it can be scratched by quartz (7), then it's hardness is between 6 and 7. An example of a mineral that has a hardness between 6 and 7 is pyrite (6 to 6.5).

To use the hardness scale, try to scratch the surface of an unknown sample with a mineral or substance from the hardness scale (these are known samples).

If the unknown sample cannot be scratched by feldspar (6) but it can be scratched by quartz (7), then it's hardness is between 6 and 7.

An example of a mineral that has a hardness between 6 and 7 is pyrite (6 to 6.5).

Hardness If the minerals on the hardness scale are not accessible, use common household items. So if there was an unknown mineral that could be scratched by the knife but could not be scratched by the glass, then the hardness would be between 5.5 and 6.5. Emery cloth Steel knife Glass Penny Fingernail 8.5 6.5 5.5 3.5 2.5 Common Objects and Their Hardness Values

If the minerals on the hardness scale are not accessible, use common household items.

So if there was an unknown mineral that could be scratched by the knife but could not be scratched by the glass, then the hardness would be between 5.5 and 6.5.

Streak When a mineral is rubbed firmly across an unglazed tile of white porcelain (a streak plate), it leaves a line of powder. This is called the streak. The color of the streak is always the same, whether or not the mineral has impurities. For example, quartz leaves a white streak, whether it's violet (amethyst), pink (rose quartz), or brown (smoky quartz).

When a mineral is rubbed firmly across an unglazed tile of white porcelain (a streak plate), it leaves a line of powder.

This is called the streak.

The color of the streak is always the same, whether or not the mineral has impurities.

For example, quartz leaves a white streak, whether it's violet (amethyst), pink (rose quartz), or brown (smoky quartz).

Streak

Acid Reaction Some minerals contain elements that react with acids to produce gases. The carbonate minerals have this reaction. Carbonate minerals are minerals that contain carbon. Calcite is an example of a carbonate mineral.

Some minerals contain elements that react with acids to produce gases.

The carbonate minerals have this reaction.

Carbonate minerals are minerals that contain carbon.

Calcite is an example of a carbonate mineral.

Florescence Florescence is whether or not the mineral glows under a black light. The fluorescent minerals are minerals that emit visible light when activated by invisible ultraviolet light (UV), X-rays and/or electron beams Activator elements are responsible for fluorescence. But not all specimens have these activator elements.

Florescence is whether or not the mineral glows under a black light.

The fluorescent minerals are minerals that emit visible light when activated by invisible ultraviolet light (UV), X-rays and/or electron beams

Activator elements are responsible for fluorescence. But not all specimens have these activator elements.

Florescence Florescent Calcite Florescent Gypsum

Review What is a mineral? What are six characteristics that can be used to identify minerals? What is luster? What is hardness? What are crystals? What is streak? What is fluorescence?

What is a mineral?

What are six characteristics that can be used to identify minerals?

What is luster?

What is hardness?

What are crystals?

What is streak?

What is fluorescence?

Copyright Information All information was retrieved from research done on the internet in February 2007. All pictures were retrieved from a Yahoo image search in February 2007.

All information was retrieved from research done on the internet in February 2007.

All pictures were retrieved from a Yahoo image search in February 2007.