Properties of Minerals Chapter F4 Section 1 Properties of Minerals

What 5 general properties do all minerals have? Inorganic Solid Crystal structure Definite chemical composition Naturally occurring

1. They must be inorganic. The mineral can’t come from or be created by anything that is living or once living.

2. The mineral must be a solid. No gas or liquid material can ever be considered a mineral. It has a definite shape and volume.

3. Minerals must have a crystal structure. Crystals have flat surfaces that meet at sharp borders or corners. They are typically made of repeating patterns in their molecular make up.

4.The have a definite chemical composition Each are made up of one type of chemical compound which are substances that have a combination of elements in definite proportions. No mineral can be made up of more than one type of compound.

And 5. They must also be naturally occurring. Minerals are not artificial; that is, they are not man made.

There are many different types of minerals, how can they be identified / classified? Each mineral has its own specific property that can be tested to identify the mineral.

1. Hardness Minerals are ranked by how they are hard or soft depending on their resistance to be scratched. It uses the Moh’s Hardness scale that ranks 10 minerals by hardness. The softest, talc, is ranked 1 and the hardest, diamond, is ranked 10. All other minerals are ranked through this system.

http://www.u.arizona.edu/~calugo/lab2/hardness.gif

http://www.geology.sdsu.edu/visualgeology/geology101/hardscale.jpg

Unpolished Diamond (10) http://www2.vscc.cc.tn.us/svinson/geo100/library/minerals/large/talc.jpg  Talc (1) Unpolished Diamond (10) http://www.nrcan.gc.ca/gsc/mrd/projects/thematic/images/diamond.jpg

This is easily an observable physical property of the mineral. 2. Color http://webexhibits.org/pigments/indiv/i/32mineral/malachite.jpg This is easily an observable physical property of the mineral. http://www.mineralminers.com/images/amethyst/mins/amem169.jpg http://www.pdvsa.com/lexico/museo/image/mineral.gif

3. Streak Sometimes color is very deceiving. Gold and pyrite (Fools Gold) have the same color. However, if both were scratched on a ceramic tile or streak plate the color of the powder left behind are different. Gold  Yellow streak Pyrite  Black Streak

Pyrite  Can you guess which one is gold? Gold 

4. Luster This is how the mineral reflects light. They can be described as metallic, nonmetallic, waxy, resinous, glassy, etc.

http://mineral.galleries.com/minerals/property/luster.htm

5. Density Each mineral has a different mass per unit volume. It is the amount of matter in a given amount of space. Some feel “heavier” than others for their size.

Density = Mass / Volume http://www.astronomynotes.com/solarsys/density.gif

6. Crystal Systems They can belong to one of six crystal systems (p. F124): Cubic Tetragonal Hexagonal Orthorhombic Monoclinic Triclinic

http://mineral.galleries.com/minerals/symmetry/symmetry.htm

These are the ways a mineral break. 7. Cleavage and Fracture. These are the ways a mineral break. A cleavage is a clean break with flat sides. A fracture is not an even break and the surface is rough or jagged. http://lewis.up.edu/mcs/wasowski/sci110/TnTkCh02/sld020.htm http://www.cobweb.net/~bug2/rock4.htm#FC

8. Special Properties. Some minerals have properties that are just unique to it. Some will dissolve under acid. Others are fluorescent or glow under an ultraviolet light. Yet, others have electrical properties when they rub or pressed against each other; this is called piezoelectric.

Why wouldn’t coal be considered a mineral? Although coal is made up of carbon such as diamonds, it was once made from organic matter.

Myth about coal. Contrary to popular belief diamonds don’t come from coal. It requires temperatures and pressure found deep within the Earth where no living organism can be deposited.

Based on what you know about what a mineral is would snow be considered a mineral?

Chapter 4 Section 2: How Minerals Form

How are minerals formed? http://www.mjr.com/images/sub_page/consumables/lava.jpg How are minerals formed? As molten rock cools, crystallization could occur. Crystallization could also occur in solution, dissolved material in water.

http://www.video-hawaii.com/dreams/free/lava.into.sea.jpg

http://whyfiles.org/031volcano/images/lava.jpg

What could affect the size of crystals formed from magma? Cooling rate Amount of gas Chemical composition

http://www.geoprime.com/Flambeau/Flambeaumine/images/copyofflamecuprite1.jpg http://people.interaction-ivrea.it/c.noessel/summ02/images/alma180252.jpg Cooling Rate. Faster cooling rate yields small crystals especially from lava. Slower cooling rate allows time to form larger crystals especially from magma.

Amount of gas or chemical composition. http://www.geobop.com/World/NA/US/1Images/Geo/QuartzAR.jpg Amount of gas or chemical composition. Certain types of gases can form large or small crystals Certain types of chemical composition could also form large or small crystals

What is a solution? It is a well mixed mixture It is a mixture which one substance dissolved another

How do minerals form from a hot water solution? Hot water solution cools. Elements and compounds leave the solution. Crystallization begins.

Solution Before http://mmtsb.scripps.edu/viper/CRYSTALS/XTAL1/cryst2.jpeg

Solution After http://www.goodearthgraphics.com/virtcave/stalmite/towers.jpg

More example of Mineral from solutions: Stalactites, Stalagmites and Columns http://www.goodearthgraphics.com/virtcave/stalmite/tolkien.jpg

Other Cave minerals http://www.social-dancing.com/Gallery/MammothCave760x496.jpg

Unique Cave Minerals http://www.electric-lady-land.com/fluorescent_minerals.html

And More Cave Minerals http://www.electric-lady-land.com/fluorescent_minerals.html

What is a mineral vein? A channel or slab of a mineral that’s different from the surrounding rock.

How does a mineral vein form? They form deep within the Earth as hot water solutions flow into cracks in the rock, cool and crystallizes.

Sulphide-bearing quartz-carbonate vein http://web.uct.ac.za/depts/geolsci/dlr/images/pl95a.jpg

Serpentine Vein http://www.ewebtribe.com/StarSpiderDancing/south/serpent1.jpg

At the Mid-Ocean Ridge. Ocean water flows into the cracks which gets heated from the magma and minerals are mixed into it. When that form of hot solution flows upward into cold sea water crystallization occurs.

How do minerals form from evaporation? As solutions lose all its water or evaporate, crystallization could occur. This is how you can make rock candy or rock salt.

Curse of Copper

Curse of Copper

Chapter F4 Section 3 Mineral Resources

What are gemstones? They are any hard mineral that are clear or colorful with a brilliant or glassy luster. Gems however are the cut and polished product that come from gemstones. http://www.gemstone.org/image_library_frameset.html Gemstone / Rough Cut and polished sunstone gem.

What are some common uses of gems and gemstones? Jewelry / Decoration Mechanical parts / machinery Grinding and polishing elements http://www.gemstone.org/image_library_frameset.html

Why are metals useful? They can be stretched into wire. Used as light bulb filament. Steel girders for buildings. Coins / currency. Manufacturing (automobiles, appliances, etc.) Artwork (paints, statues, etc.)

How can a rock be considered an ore? It must contain metals or some economically useful mineral. Economically useful means it is profitable. It can be mined for a profit IMPORTANT: most metals do not occur in it’s pure or native form. Galena (below) – lead, bauxite – aluminum, etc. http://volcano.und.nodak.edu/vwdocs/minerals/bauxite.html http://www.google.com/search?sourceid=navclient&ie=UTF-8&q=strip+mining

How can a rock be considered an ore? Gold, silver and platinum are examples of metals that DO occur in its native form. http://www.google.com/search?sourceid=navclient&ie=UTF-8&q=strip+mining

What does a prospector do? They are geologists that look for ore deposits. They not only look at the type of rocks but also plants and water for specific chemicals that are clues to the presence of specific minerals. http://www.goldprospecting.com/index2.html

List 3 types of mines and how the ore deposits are extracted. Open pit mine – ores start on the surface and then extend deep in the ground. Shaft mine – ores are found in veins where tunnels are created to follow it. Strip mine – ores are exposed and collected from the surface.

How do you strip mine? Use heavy earth moving equipment to scrape away soil on the surface. http://www.wvgazette.com/static/series/mining/STRIP3.JPG

How do you pit mine? http://en.wikipedia.org/wiki/Image:Chino_copper_mine.jpg Also uses heavy earth moving equipment to dig a huge hole / pit and remove ores.

How do you shaft mine? http://www.me.mtu.edu/~jdschust/cliffs/csmimages.html Use tunneling equipment to create tunnels deep underground that follow veins of ore.

Shaft Mine Surface http://www.me.mtu.edu/~jdschust/cliffs/csmimages.html

What are some problems with mining? They can destroy the land and habitat. They can pollute the rivers and lakes. http://www.mii.org/coal/coal.html

How can we reduce the amount of damage made by mining? By restoring (or reclaiming) the soil that was lost through the mining process. http://www.mii.org/coal/coal.html

Before

After

Before and After http://www.personal.psu.edu/users/n/p/npn107/reclamation.html

Reclamation!!!

Reclamation!!!

What is the purpose of smelting? To separate useful metal from other elements. This is usually done by melting or baking the ore with other chemicals so that the impurities will react with the chemicals and leave the metal behind. Along with the metal, it leaves behind and unusable material called slag which are usually a pollutant.

What is the purpose of mixing 2 or more metals together? What are alloys? They are a mixture of 2 or more metals. What is the purpose of mixing 2 or more metals together? To make it harder or less resistant to rusting.

Titanium alloy – Iron, Aluminum and Titanium with others nonmetallic elements http://www.google.com/search?sourceid=navclient&ie=UTF-8&q=strip+mining