Geol. 198B Homework #10: Gem Formation 20 pts. **

The answers to the following questions will be found in the text reading assignment, and the assigned web essays for Lesson 10.

Required Format: A 2 point penalty will be deducted for not following the format described (even if all the answers are correct)!

Send the answers to me, as an email through WebCT. Use "Homework #10" as the subject line.

As the body of the email, the answers should be arranged vertically, single file, like so:

1. b

2. quartz

3. False

4. etc....

All except one of the required answers for Homework #10 is either a multiple choice letter, or a single word fill in the blank. One question requires a written out answer.

When the time period for homework submission has passed, grades will be posted which you may then view using the "My Grades" function of WebCT through the course home page.


1. Which gemstone has a longer history of use (choose one: malachite/ Sugilite).


2. An example of a gemstone species with a world-wide distribution is:


3. The crystal system to which malachite belongs is the ____________ system.


4. If you saw a rock that was composed of layers, you would conclude it is most likely a/an ______________ rock.

a. fossil

b. igneous

c. eluvial

d. alluvial

e. sedimentary

5. Describe an appropriate test for an opaque purple gem you were told was Sugilite, by which you could determine if it was a plastic imitation: (go beyond naming the test, tell how it is done and what results would confirm or rule out plastic)







6. Lyman describes the baking of bread from flour and water dough as similar to the geologic process of:

a. metamorphism

b. volcanism

c. eruption

d. plate tectonics

e. sedimentation

7. Malachite is considered a _____________ mineral because its formation depends on chemical interactions between pre-existing minerals and mineral solutions.

a. secondary

b. tertiary

c. primary

d. soluble

e. complex silicate

8. The sole source of gem grade Sugilite on today's market is located in:

a. The Democratic Republic of Congo

b. Japan

c. Southern Africa, in the Kalahari Desert

d. Russia

e. USA

9. Which country is shown on Hall's world map diagram as yielding the greatest variety of different gemstones?


10. Those involved in fashioning malachite need to protect themselves from inhaling the dust, which is toxic due to the ____________ it contains.

a. carbon

b. copper

c. arsenic

d. lead

e. asbestos


** "A Word to the Wise": In order to get the full 20 points on this, and every other homework, you must have all the correct answers, they must be in proper format as described above AND your email to me must be received and logged in by WebCT before the closing time for the assignment. As there are inevitable computer downtimes, disconnects and other such issues, I suggest that you do not wait until the very last moment to attempt to submit the work.