TY  - BOOK
AU  - Dietrich, Richard Vincent
AU  -  Skinner, Brian J.
TI  - Gems, granites, and gravels : knowing and using rocks and minerals
SN  - 0-521-34444-1
U1  - 549 
PY  - 1990///
CY  - America
PB  - Cambridge University Press
KW  - Mineralogy	
KW  -  Petrology
ER  -