AURIFEROUS QUARTZ. * 

 taining minute quantities of gold. It occurs 

 in most gold regions. 



AuKiFERous Quartz. Veins chiefly com- 

 posed of Quartz containing Native Gold are 

 found in North Wales, Spain, Portugal, 

 California, Australia, and other countries. 

 Several veins of this character occur near 

 Dolgelly, in Merionethshirre. 



Specimens of gold-bearing Quartz from the 

 Grass Valley, Nevada county, California, 

 will be found in the entrance-hall of the 

 Museum of Practical Geology. See also 

 Case 11, Principal Floor (Australia). 



AuROTELLURiTE. Haidinger. A variety 

 of Sylvanite from Nagyag in Transylvania, 

 "where it is associated with Blende, Grey 

 Copper ore, and Copper Pyrites, with Quartz 

 and Brown Spar. Colour silver-white, in- 

 clining to brass-yellow, and sometimes to 

 grey. Occurs disseminated and crystallized 

 in very small, rather broad, four- sided 

 prisms. Sectile. S. G. 7-99 to 8-33. 

 Analysis of yellow crystals, by Petz : 

 Tellurium .... 51-52 

 Antimony . . , .6*75 



Gold 27-10 



Silver 7-47 



Lead 8-16 



100-00 



Affords a grass-green solution in nitric 



acid, with the evolution of much nitrogen. 



As it contains a considerable quantity both 



of gold and silver, Aurotellurite is worked 



on account of both those metals. 



Brit. Mus., Case 49. 



f Names for Na- 



. -rw I tive Telluri- 



AuKUM Paradoxum, ' ^^^^^ .^^ 



AuRUM Problematicum.] ^i^i^rworkson 

 [_ Mineralogy. 

 AuTOMALiTE, Nicol, Phillips. Automa- 

 i.iTH, Werner. Automolite, Dana. A Zinc- 

 Spinel. Occurs in octahedrons and in tetra- 

 hedrons, of which the angles are replaced : 

 also macled. Colour dark green or black ; 

 dark bluish- green by transmitted light. 

 Nearly opaque. Lustre vitreous, inclining 

 to resinous. Streak grey. Brittle. Fracture 

 splintery or conchoidal. H. 8. S.G. 4-1 to 4-6. 



Comp. Zn Al. 



Analysis from Fahlun, by Ekeberq : 

 Alumina .... 60 -00 

 Oxide of zinc . . . 24 25 

 Peroxide of iron . . .9 25 



Silica 4-75 



Protoxide of manganese . trace 



•25 



AXINITE. 33 



BB alone, unaltered ; and near]}- so with 

 borax and salt of phosphorus. 



Not acted on by acids or alkalis. 



Localities. Fahlun in Sweden, in talcose 

 slate. Near Sather and Garpenberg in 

 Sweden, compact, Franklin, New Jersey, 

 with Quartz, Felspar, and Jeffersonite. 

 Haddam, Connecticut ; in Granite associated 

 with Chrysoberyl, Garnet and Tantalite. 



Name. From a.vro!/,oXo;, a deserter; in al- 

 lusion to the presence of oxide of zinc in 

 a mineral not resembling an ore. 



Brit. Mus., Case 19. 



AuTUNiTE, Brooke §• Miller, Greg &,- 

 Lettsom. A name given to the yellow- 

 phosphate of Uranium and Lime (Uranite) 

 from its occurrence in the neighbourhood of 

 Autun in F' ranee. 



It has also been found in Cornwall at 

 South Basset, Tolcarne mine, and Hue! 

 Edwards. 



Fig. 33. 



AxESTONE, (Jameson), a name for Jade ; 

 in consequence of its being used by the New 

 Zealanders for axes and otfensive weapons. 

 See Nephrite. 



AxiNiTE, Dana, Haily, Nicol, Phillips. 

 Anorthic. This mineral is seldom found 

 massive, oftener disseminated, but most fre- 

 quently crystallized in very oblique rhom- 

 boidal prisms, which are often so flat as to 

 appear tabular. Its most common colour is 

 violet or clove-brown of various shades, 

 passing into plum-blue or pearl-grey, and 

 greyish -black. Lustre brilliant externally, 

 of fractured surface vitreous. Transparent to 

 translucent. Streak uncoloured. Easily 

 frangible. Fracture in transparent varie- 

 ties, small and imperfectly conchoidal. Be- 



Fig. 34. 



Fig. 35. 



Fig. 36. 



comes electric by heat or friction. Exhibits 

 trichroism ; different colours, as cinnamon- 

 brown, violet-blue, olive-green being seen 

 in different directions, while "on looking 

 through a crystal in the direction of the 

 optic axis, a dark-violet stripe is seen, 

 which is interrupted at the point occupied 

 by the axis." H. 6-5 to 7. S. G. 3-27. 



