Below is the link to my powerpoint on Minerals. The link below it is the corresponding notesheet for the Mineral Powerpoint





Mineral Quiz taken on Tuesday, November 24th

http://www.quia.com/quiz/2048137.html

Minerals

Minerals are naturally occurring, inorganic solids with a definite set of chemical and physical properties.

Therefore, minerals can not be man-made, can never have been living, and can only exist in the solid state.

Chemical Properties


Minerals are composed of either an individual element or a compound of elements.

Minerals that form from compounds of elements can be classified by there chemical composition into groups or families of minerals.

  • the two most common elements found in the Earth's crust are Silicon and Oxygen
  • a list of the most common elements found in the Earth's crust can be found on the front page of the ESRT

Mineral Groups


Native Minerals

  • minerals which are composed of only one element aand are more common among metals such as gold and copper.

Silicates

  • Contain Silicon and Oxygen in various ratios in their chemical composition
  • Are the most abundant group of minerals
  • Examples are quartz, muscovite mica, and garnet

Sulfides

Oxides

Sulfates

Chlorides

Carbonates


Physical Properties


Minerals can be identified based on a set of physical properties which each mineral possesses. Each mineral's physical properties are determined by the internal arrangement of the atoms inside the mineral.

Luster is the way in which a mineral reflects light from its surface

Metallic luster - when a mineral looks like metal when reflecting light
galena.jpg


Nonmetallic luster - when a mineral does not shine like metal in reflecting light. Their are several varieties or subcategories of nonmetallic luster. They include dull, earthy, waxy, vitreous, pearly, and adamantine.
Examples:

waxy.jpg
Chalcedony
Waxy Luster (Chalcedony)


vitreous.jpg
Quartz
Vitreous Luster (quartz)


adamantine.jpg
Diamond
Adamantine Luster (diamond)


Hardness is a measure of how easily a mineral can be scratched.
Freidrich Moh was a German geologist who developed a scale by which an unknown minerals hardness could be compared to the hardness of ten minerals. It is known as Moh's scale of hardness .

Moh's Scale of Hardness
1 Talc
2 Gypsum 2.5 fingernail
3 Calcite
4 Fluorite
5 Apatite 5.5 glass
6 Feldspar
7 Quartz
8 Topaz
9 Corundum
10 Diamond


To identify hardness a mineral is first scratched against a glass plate. The hardness of glass is 5.5. If the mineral scratches the glass then it has a hardness greater then 5.5. If the mineral is softer then glass you may want to try using your fingernail to scratch the mineral. Your fingernail has a hardness of 2.5. If your fingernail can scratch the mineral it has a hardness less then 2.5, if not the mineral's hardness ranges from 2.5 - 5.5.

Cleavage and Fracture (Breakage Pattern)

Minerals break along planes where atomic bonding is weak. A mineral is said to have cleavage if it splits relatively easily and evenly along one or more flat planes. A mineral with cleavage may break in either one, two, or three planes. Here are some common examples of various types of mineral cleavage.


If the bonding between atoms is tight, then the mineral may break with rough or jagged edges. This uneven breaking is referred to as fracture.


Streak is the color of a mineral's powder when scraped along an unglazed tile.

Below is a short video on how to determine the streak of a mineral:

Color Is the least useful property used in mineral identification because many minerals may be the same color, and many minerals occur in nature with a variety of colors.

  • Colors of minerals can be vary due to small impurities of other elements in the composition of the mineral.

Identifying Minerals

To identify a mineral you must first test all of the physical properties above. You can then use the ESRT Properties of Common Minerals chart to identify the minerals name.


Special Properties Double Refraction
calcite-double-refraction-124.jpg

Calcite

Magnetism -
Magnetite.jpg

Magnetite

Fluorescence -

fluorescent-minerals.jpg



Funny video on minerals and rocks
http://www.teachertube.com/viewVideo.php?video_id=1256