Read P G <br/><br/>
Dictionary of gemmology 
Read P G 
 - Ed 2 
 - London  Butterworth        1988 
 - 265p  cm. 
<br/><br/><label>Standard No.: </label>29260 
<br/><br/><label>Source: </label> Reference Collections 
<br/><br/><label>Subjects--Topical Terms: </label><br/>GEOLOGY
<br/><br/><label>Dewey Class. No.: </label>H19k, M8(RR)