Re: How can you differentiate between white marble and white quartzite?

Jaime:

White marble and white quartzite may look similar superficially, but they 
are actually very different and easy to tell apart. 

1. Quartzite is harder and will scratch glass. Marble will not.
2. marble will fizz gently in dilute (10%) hydrochloric acid. You may need 
to scratch the surface, and look at it with a hand lens. Be careful. Even 
dilute acid can hurt your eyes and rot your clothing.

These are just two of the obvious differences. Marble is made of calcite or 
dolomite (or both) and quartzite is made of quartz. The crystals of these 
three minerals have different shapes, and the quartz crystals are shinier. 
You can find out more about telling the differences among minerals with an 
introductory college level mineralogy textbook. Some books for mineral 
collectors are also helpful. 

Hope this helps.

David Kopaska-Merkel
Geological Survey of Alabama
PO Box 869999
Tuscaloosa AL 35486-6999
(205) 349-2852
FAX (205) 349-2861
www.gsa.state.al.us