TY  - BOOK
AU  -  Read,Peter G.
TI  -  Gemmological insruments : :  their use and principles of operation / 
U1  -  553.8 REA 
PY  - 1983///
CY  -  London : 
PB  -  Butterworths, 
KW  -  Precious stones
KW  -  Instruments
KW  -  Tests
ER  -