TY  - BOOK
AU  - Kraus, Edward Henry,
AU  - Slawson, Chester Baker,
TI  - Gems and gem materials
SN  - 070353611
AV  - QE392 .K7 1947
U1  - 549 
PY  - 1947///
CY  - New York
PB  - McGraw-Hill Book
KW  - Precious stones
N1  - Includes bibliographical references and index
ER  -