Anderson, B. W.  1901- <br/><br/>
Gem testing / 
B.W. Anderson. 
 - 9th ed. 
 - London :  Butterworth Scientific,  1980. 
 - (432) p. ;  22 cm. 
<br/><br/><label>ISBN: </label>0408004401 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Precious stones--Identification.<br/>Precious stones--Testing.