Webster, Robert. <br/><br/>
The Gemmologists' compendium / 
By Robert Webster. 
 - London :   N.A.G. Press,   1975. 
 - 235 p. :   il. ;  19 cm. 
 - 679.8 (NLA) .
<br/><br/><label>ISBN: </label>719800013 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Stone technology<br/>Gemstones
<br/><br/><label>Universal Decimal Class. No.: </label>679.8 (NLA)