What is a mineral?
I like and use the following definition, which is essentially the strictest form of the definition: A naturally occurring, homogeneous inorganic solid substance having a definite chemical composition and a characteristic regularly repeating internal crystalline structure.
To a mineralogist, that all means that a mineral is NOT man-made. It is a solid. It is not formed by a process from a living organism. It is crystalline and has very limited variation and as such, can be defined by a chemical formula.
More or less. I'll say more about that later.
To a Natural Resource Scientist, pretty much as long as it comes out of the ground, it is a mineral resource. Even water is classed as a mineral resource from that perspective.
Again, more or less. Definitions vary depending upon the source.
A scientific discussion of nomenclature (naming and classification) of minerals can be found
here: International Mineralogical Association.
Knowing that, here is your assignment for today. It should take no longer than a class period, as long as you get started quickly.
Go to the following web sites to find minerals that show the properties listed below. (computer #1 does #1 only, #2 does only #2, etc.) you WILL have to know the properties on a test later.
Explain the property listed for your computer number, then list a mineral which exhibits that property.
Write a report/essay about the mineral, and include the following: all it's distinguishing properties, particularly those most useful in identifying the mineral, plus it's importance or uses - if it has any - and locations where major deposits can be found.
This is a WRITING assignment, and WILL be graded on grammar, punctuation, and spelling.
DO NOT JUST COPY AND PASTE (with the exception of what is listed at the page bottom)- That is PLAGIARISM on a written assignment.
***NOTE*** You first must understand each mineral property in order to properly do this exercise, so you may wish to go to the mineral intro link before you attempt to do any writing.
Get a good understanding of the property about which you are to write. Then go to the different web sites via the links from this page, find the property, and go for it!
One site which is particularly good for mineral property descriptions is the Physical Geology page at Blackhawk College:
When you get to this web site, click on the link for lecture materials in the left margin, then scroll down and click on both links beginning with "Mineral". Read that material; when you finish, click on the link at the page bottom "Additional information and identification exercises can be found at:
Mineral Physical Properties and Mineral Identification ". This will take you to the lab materials which will only help your understanding of mineral properties.
Now go to the different web sites below via the links from this page, find a mineral that shows the specific property you are to find, and go for it!
mineral properties links
Introductory material about mineral properties by David J. Leveson
mineral intro links
This is Amethyst Galleries, a commercial web site which has lot's of good information!
A large mineral database with much useful information about minerals and mineral properties.
This is a mineral identification key - which also explains how to identify minerals using their various properties.
This is probably the most detailed database about minerals on the Internet.
This is a site with MANY links to other web pages about minerals and mineral properties.
mineralogy links and more
Another database which lists minerals by name....
Minerals By Name
Here are the mineral properties listed by computer number about which you are to research.
Note: Find a mineral that exhibits the property shown, then write about the mineral; include anything about that mineral (including the specific property which you will need to describe)which would help in it's identification. Include localities where it can be found (especially any famous locations), general occurrence, related minerals, crystal form, any non-crystal forms, what are its uses, etc.
Computer# - mineral property
1. Has a silky luster
2. Has a fibrous luster.
3. Has a conchoidal fracture
4. Has a reddish brown streak.
5. Has a yellow streak
6. Is an ore of mercury
7. Has double refraction
8. Shows dichroism
9. Has a hardness of 1 (some mineral other than talc)
10. Has a Hardness of 8 (some mineral other than topaz)
11. Has a Pearly luster
12. Has a rosette noncrystal form or habit
13. Has a radiating noncrystal form or habit
14. Has dodecahedral cleavage
15. Has octahedral cleavage
16. Has a dendritic noncrystal form or habit
17. Shows flexible tenacity
18. Shows elastic tenacity
19. Is malleable tenacity
20. It fluoresces a green color
21. Is radioactive
22. Is magnetic - exhibits magnetism.(Do a mineral other than magnetite)
23. Shows effervescence (a mineral other than calcite) NOTE: this is NOT the band Evanescence....
24. Has asterism
25. Has a Red streak
26. Crystals are in the Hexagonal crystal system
27. Crystals are in the Cubic (or isometric) crystal system
28. Crystals are in the Triclinic crystal system
29. Crystals are in the Monoclinic crystal system
30. Has a Blue streak
31. Has a Green streak
32. Crystals are in the Tetragonal crystal system
One last detail. If you STILL don't know what the different mineral properties are, then go back to the pages listed above and review them.
For 4 points extra credit, define the following terms - you CAN do a "cut and paste" - print them out, and turn them in on Friday.
These WILL be on your next test!
#9 through 14 will be defined by the number of axes plus the axes length and the angle at which they meet. Example: The Cubic crystal system has 3 axes, all the same length, all meeting at 90 degree angles.
4. specific gravity
9. cubic crystal system
10. tetragonal crystal system
11. orthorhombic crystal system
12. hexagonal crystal system
13. monoclinic crystal system
14. triclinic crystal system
18. Double refraction