Opal town 
Rob Waring, series editor; National Geographic Society 
 - London :   Heinle, Cengage Learning,   c2009. 
 - 24 p. :   col. ill., map   21 cm.  
 - Footprint reading library .
<br/><br/> People from around the world travel to Coober Pedy, Australia, with hopes of getting rich. This town is full of valuable stones called 'opals'. Some opals are worth millions, but they are extremely hard to find. What influences the value of an opal? What does it take to find them?  
<br/><br/><label>ISBN: </label>9781424021963 
<br/><br/><label>Subjects--Topical Terms: </label><br/>English language--Textbooks for foreign speakers
<br/><br/><label>Dewey Class. No.: </label>428 OP AL