QUA 



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QUA 



terminated by pyramidal points ; 

 but it also occurs in many deriva- 

 tive forms, its primitive being a 

 rhomboid. The primitive crystal 

 of quartz, says Phillips, is con- 

 sidered to be an an obtuse rhomboid, 

 of which the angles are given by 

 Haiiy in his Tableau Comparatif, 

 as being 94 24' and 85 36'. A 

 minute examination of several 

 specimens afforded perfect coinci- 

 dences of 94 15' on the one angle, 

 and 85 45' on the other, the 

 former differs from that given by 

 Haiiy, in being 9' less; the latter 

 in being 9' more. It scratches 

 glass, of which it is an essential 

 ingredient ; it gives sparks with 

 steel in great abundance. Hard- 

 ness = 7. Specific gravity = 2-5, 

 to 2 % 7. Its lustre ranges from 

 splendent to glimmering, and is 

 vitreous. Fracture conchoidal. 

 Brittle, and easily frangible. It 

 exhibits double refraction, which 

 must be observed by viewing an 

 object through one face of the 

 pyramid and the opposite side of 

 the prism. It is infusible before 

 the blow -pipe, even when the flame 

 is excited by oxygen. Before the 

 compound blow-pipe a fragment of 

 rock crystal fuses instantly into a 

 white glass. Quartz is very gene- 

 rally distributed, and,, as far as our 

 knowledge extends at present, 

 appears to be the most abundant 

 mineral in nature. It occurs in 

 every rock, from granite to the 

 newest secondary formation ; it is 

 found in every district of the globe. 

 "When mixed with alkalies quartz 

 melts easily, and forms glass. It 

 is not acted upon by any acid but 

 the fluoric. Quartz often encloses, 

 or is mixed up with, foreign sub- 

 stances, from which circumstance 

 it assumes great varieties of colour. 

 Many of the precious stones consist 

 of simple quartz combined with 

 some colouring matter. Among 

 these we may place the amethyst, 



cats' -eye, opal, Bristol diamond, 

 Scotch topaz, &c. Professor Jame- 

 son divides quartz into six sub- 

 species, namely amethyst, rock 

 crystal, "rose or milk quartz, 

 common quartz, prase, and cats 3 - 

 eye. Quartz exists in veins inter- 

 secting mountains, and it some- 

 times forms large beds, and even 

 entire mountains, which are com- 

 posed of this mineral in grains 

 united without a cement, called 

 granular quartz. Combined with 

 alumine and iron, quartz loses its 

 translucency and passes into jasper. 

 When rubbed, quartz yields a 

 peculiar odour, and a phosphores- 

 cent li}*ht. Quartz is a constituent 

 of granite. 



QFA'RTZOSE. } Containing quartz; com- 

 QUA'RTZY. j posed of quartz ; re- 

 sembling quartz ; having the 

 properties of quartz. 

 QTJAET'ZOSE CONGLOMERATE. | The 

 OLD RED CONGLOMERATE. j name 

 given to the upper division of the 

 ]N"ew Eed System of Murchison. 

 When the coverings of turf or bog 

 are removed from the old red sand- 

 stone, "a conglomerate," says Sir 

 E. Murchison, "composed of peb- 

 bles of white quartz in a red matrix, 

 forms the upper member of the 

 old red sandstone, or substratum 

 of the carboniferous limestone." 

 QUARTZ ROCK. ) A compact, fine-grain- 

 QUART'ZITE. J ed but distinctly 

 granular rock, very hard, frequently 

 brittle, and often so divided by 

 joints as to split in all directions 

 into small angular but more or less 

 cuboidal fragments. Juices. 

 QUATE'RNART. (quaternarius, Lat. 

 quaternaire, Pr.) Consisting of 

 four ; the number four. In 

 geology, a term applied to the 

 upper tertiary strata, or those 

 which are supposed to be of later 

 formation than any of the strata in 

 the Paris or London basins. The 

 faluns, or marls of Tourraine and 

 the Loire, are quaternary formations. 



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