139 



Crystallised quartz sliowing one termination only is exhibited 

 from many localities ; in particular from the Dutchman's Lode 

 (tin), ]S"ew England, from the hematite mines of Cumbeiiand 

 (Eng.), and the lead mines of Weardale (Eng.). Those from 

 Cumberland are associated with specular iron. 



Quartz crystals vary much in their lialit without losing the 

 general characteristics above described. Thus, 5891, Bora Creek, 

 and 8027, New England, show a long slender prism, while 6985, 

 America, has a prism, but slightly developed compared with the 

 pyramid. The excessive development of certain crystal faces 

 leads to distorted forms (see fig. B on page 138) . Thus in 4000, 

 Eish Eiver Creek, two parallel faces of the prism have grown 

 to a much greater extent than the other four, giving rise to a 

 tabular form. 



9076, Kingsgate : shows one crystal invested by another. The 

 inner crystal is of earlier date than the outer. It would appear 

 to have ceased to grow for a while, and then to have resumed its 

 growth when favourable conditions again prevailed. 



Quartz very frequently contains inclusions of other minerals. 

 The Cumberland specimens above alluded to contain hematite. 

 97 and 9173, Kingsgate : contain respectively mispicJcel and 

 native lismuth. 95, Vermont, U.S.A. ; 7444, Madagascar, and 

 the Cairngorn, 8735, Tingha : contain strings of rutile. 



Quartz may be coloured by pigments : — 6970, Glen Innes : 

 red. 1749, Broken Hill, and 6840, Eussia : blue. 94, Moonbi, 

 and 5181, Werris Creek : green. 



Enliydros. — These consist of quartz or chalcedony, or both. 

 They are hollow, frequently containing a liquid ; and are not 

 true crystals or pseudomorphs. Magnificent specimens have been 

 found at Kingsgate, but the museum does not possess one. 

 Those exhibited (5902, 5162) are from Spring Creek, Beech worth, 

 Victoria. 



Cairngorm. — Smoky quartz : Uralla, Tingha, Umeralla, Kings- 

 gate, Solferino, Meadow Elat, and elsewhere. 



