Initial Publication Date: June 28, 2005

Unknown #4

Download and view the crystal structure data

  1. Right click on Unknown_4.amc ( 586bytes Dec30 04) to download the crystal structure to your computer. (This file was modified from an AMC file in the American Mineralogist Crystal Structure Database).
  2. Once the file has downloaded to your computer, click on it to automatically start XtalDraw and open the file for viewing. You should see something like this...
  3. Try to resist looking at the mineral chemical formula (Edit > Chemical Formula) as this will probably be too big of a hint right off the bat.
  4. XtalDraw has colored all the cations the same color. To better see the placement of the different cations in this structure, click on Edit > Atom Attributes to change the colors of the various cation sites.

Determine the identity of the unknown

Using your knowledge of crystallography and systematic mineralogy, and manipulating the downloaded structure in XtalDraw, answer the following questions to deduce the identity of the unknown. Check your answers by clicking on the "show answer" tabs which appear with each question.



...so what mineral is this?