Homework 4 – due Wednesday, 10/31

• As you now know, there are six crystal systems. For each system, do the following:

1. Find one mineral in your text that is a member of that system. More common minerals, and those that have a greater tendency to form large crystals, are preferred.
2. Write down its crystal system and class.
3. Using Table 5.4, p. 194, note its symmetry content (ignore "i" and any overbars in the table)
4. Go online and download an image of this mineral that shows a crystal, and see if you can identify the symmetry elements you found in step 3 in the image. Write down what symmetry you see in the image in a descriptive sentence or two.

• Let's save some trees - email me this homework. You can send a MS Word document (with embedded images), a PDF (with embedded images), a compressed (Zip or Stuffit is best) folder of HTML & images, or a compressed folder of plain ASCII text and images.

Links:

• You should be able to find plenty of images by searching for the mineral mane in Google.
• You can get an evaluation copy of Stuffit for free for PC and Mac from Aladdin.

Here is an example:

Vesuvianite

• Tetragonal, 4/m2/m2/m
• Symmetry Content: 1 A₄, 4 A₂, 5m
• Image. This image shows stubby tetragonal prisms. In the top crystal we are looking nearly down the A₄. A₂s are marked in red and black, and m's are marked in heavy blue: