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

 - 2nd ed. 
 - London :  Butterworths,  1970. 
<br/><br/>Bibliography: p. 780-783. 
<br/><br/><label>ISBN: </label>0408206535  L.12.00 
<br/><br/><label>LCCN: </label>78581543 
<br/><br/><label>Nat. Bib. No.: </label>B71-05646 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Precious stones.
<br/><br/><label>LC Class. No.: </label>TS752  / .W39 1970b 
<br/><br/><label>Dewey Class. No.: </label>553/.8