Colour in Minerals & Gemstones

Hi, my essay is understanding of colour, which is called “nats 1870”. The following are the requirements of the essay
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In this assignment, you will write a short essay describing the colour-causing mechanism for a
specific mineral or gemstone. The exact topic depends on the last digit of your student number.
Topic Assignments:
(based on last digit of student number)
0, 1: corundum-based gems (includes ruby, sapphire)
2, 3: diamond (includes coloured diamonds)
4, 5: amethyst & citrine
6, 7: beryl-based gems
8, 9: opal or lapis lazuli
Note: This assignment is graded according to topic. Make sure you name your file:
YOUR-TOPIC_YOUR-LASTNAME (if you do not include topic in filename, your
paper will not be graded).
Directions for essay:
• length: 5-6 pages of written text, double spaced, 11 or 12-point
• references: on additional page, in a standard format (APA, MLA, etc. – your choice)
• image: include 1 image of your mineral/gem (with citation in caption, does not count
towards page count for essay)
• structure of essay:
o introduction and general overview of colour in minerals & gemstones (1
paragraph)
o choose 3 of the colour causing mechanisms for minerals/gemstones discussed in
class, and write 1 paragraph on each mechanism (Note: these must be 3
different mechanisms from your assigned mineral/gem) (3 paragraphs)
▪ mechanisms: transition metal compound, transition metal impurity,
charge transfer, fluorescence, colour-centre, band-gap colour, doping
o mention where and how your assigned mineral/gem is found/mined; can also
include any historical context (1-2 paragraphs)
o the colour producing mechanism for you assigned mineral/gem, and if there are
variations in colour – physically how these variations are produced (2-4
paragraphs)
▪ Note: this will be the 4
th
mechanism discussed in your essay. in addition
to the 3 above.
o discussion and/or diagram of the molecular composition & crystal structure of
your assigned mineral/gemo specific uses for that mineral/gem (1-2 paragraphs) (note – these should not be
any ‘spiritual’ or ’healing’ properties)
o conclusion (1 paragraph)
o References and in text citations in proper format (eg APA or MLA)
Note: You should use in-text citations for any facts you give, and collect all of your references
in a section at the end of your essay. If you use class notes as a reference – they must be cited
Writing resources:
• See file ‘How to write an essay on a scientific topic’ on eClass
• York University Library’s SPARK resources (link on eClass)
• Use York University Library’s Style guide resources
https://researchguides.library.yorku.ca/styleguides
Any plagiarized work will automatically be dealt with according to the York Senate Policy on Academic
Honesty. http://secretariat-policies.info.yorku.ca/policies/academic-honesty-senate-policy-on/
Essay Evaluation Criteria:
• covering all requested material
• clear and effective communication of ideas
• appropriate focus, level, depth
• organization, grammar
• proper use of references: format, in-text citations (can cite Lectures)
Details are in the pdf below.

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