Webster, Robert <br/><br/>
Gems:   Their sources, descriptions and identification  

 - London:   Butterworths & Co. (Publishers) Ltd.,   1975 
 - xviii, 931p.  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Chemical technology 
<br/><br/><label>Subjects--Index Terms: </label>Gemstones  
<br/><br/><label>Universal Decimal Class. No.: </label>671.15  / L5