Chemistry
Gem Project
Background:
There are over 2,000 known minerals in nature. Their unique properties are well defined due to
their chemical composition and crystal structure. The minerals that are classified as gem
minerals possess both beauty and durability (due to their hardness). Beauty is classified
according to clarity, brilliance and color. Durability (hardness) is measured according to the
Mohs’ scale in which 10 is hardest. Anything with a hardness of 7+ on the Mohs’ scale is
considered durable.
Understanding the chemistry of crystals helps explain the unique characteristics of some of our
well known and most desired gems. For example: Rubies are gem minerals that are classified
in the family of corundum. Their chemical composition is Al2O3. They have a Mohs’ hardness
of 9. The unique red color of a ruby is due to the presence of Cr3+ ions in place of some of the
aluminum ions in the crystal. The finest rubies are recovered from Myanmar and Kenya.
(www.chemistryexplained.com?Fe-Ge/Gemstones.hrm#b)
Objective of project: The purpose of this project is to identify the chemical composition and
physical properties of a unique gem or mineral and share this information with the class using
an interactive slide. As a class, we will be introduced to the tool, “thinglink” which will allow our
individual research project to be complied into an interactive slide show.
What to include in this slide:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Name of the gem/mineral
Picture (to emphasis its beauty!)
Chemical formula
Mohs’ hardness/durability
Where is this located
Physical properties
Unique applications
Interesting facts.
References
Getting Started:
The following websites are useful links for information: (pathfinder available through media
center)
http://www.gemhut.com/gemidx.htm#Alphabetical
http://webmineral.com/specimens/index.php?init=D
http://www.smithsonianeducation.org/educators/lesson_plans/minerals/gems.html
Submit the completed power point to me via e-mail: cwilhelm@nhvweb.net
Deadline:
.
Friday, April 24th (at the end of class)
Grading Rubric: Gem/Mineral Research Project
Research Project (50 pts)
Impressive depth of coverage
all bullet points are met
10 9 8
Adequate coverage of
material
7 6 5 4
Little /no
Information presented
3 2 1
Adequate explanation
of chemistry
7 6 5 4
Little/no explanation
of chemistry
3 2 1
Neatly prepared, no spelling
or grammar mistakes
10 9 8
Adequate presentation few
grammar/spelling mistakes
7 6 5 4
Sloppy, many spelling and
grammar mistakes
3 2 1
Clearly presented to class
10 9 8
Limited information shared
with class
7 6 5 4
Confusing/ not presented to
the class
3 2 1
Creative, unique, fun &
informative!
5
Informative but not very
unique or creative
3
Not very informative or
creative
0
Excellent variety of
Sources (3+)
Citation in MLA format
5
Adequate variety of
Sources (at least 2)
3
Inadequate variety of sources
(0-2 references sited)
2, 1, 0
Insightful explanation
of chemistry
10 9 8
Total:
/50pts