EARTHS. SILICEOUS. 55. Quart^am. 
i6$ 
Foiinfif diffiributtd in ntoll parts of tbo globe, frcquentijf In r&« 
native oxydcs of metals and: ni’iierals, fonietimes forming 
whole rocks, and fomctimes in beds and veins; of various 
degrees of !ra.;f[jarency and colour, but generally v/hke of 
greyilh ; fpecific gravity from 26,4. to 26,5. 
taiulart. Of a conchofdal texture, in tabtilar cryilals, 
Hoffmann £ erg Jonrn. tyfiS, >,^.274. 
Found near Schenvsiz in Hungaiy, and near Freyhurg in Saxary' 
colour generally white, rarely doll grecnilh : the tables 
niollly rhombic, though fomctimes found j-ftded. 
faAkioju Of aconchoiclal texture, in cubic cryllals wliicli are fre- 
quently hollow within. 
I. With the faces fguare. 
Forn. ittd. fqf. r. p. zt. Knr/i. Leji. mix. I. p, 104, 
Hafmanri Berg, ycurtt^ 178S. 1./. 275. 
%, With the faces rhombic. 
F, Boru. ini.fff. z.p. 8g, KarH. Lefi. min. t. p. t04. 
Found in Sweden, Hungary, Saxony, aztd Bohetma, generally t 9 
aggregate cryilals which jeem to have acquired their form froB* 
fomc other cr\ Hat wntch it had enveloped, and which had 
gradually mouldered, leaving a hollow in its place ; colour 
while, hoary, roargaritaceous, or brown-red j pellacid, di- 
aphanous, or nearly opake. 
oaeidrienm Of a concPiordaf texture, tn a dotiWe 4-fided pyramid- 
Hojffmann Berg. Journ. 1788 t.p, 275, 
Found near Sdneehurg in Saxony, oftentimes hollow withitt' 
colour the fame as (j^cubicuia. 
tntdrum. Of a Cfuichoidal texture, in a fimple j-fteJed pyramid. 
Born, ind fcj. 2. p 88, 89. 
Found neat Htjlekull in Sn.aeden, near SchneeBurg in Saxony, f® 
''Sgregate cryilals which arc fometimes hollow i luftre fre- 
quently pellucid : colour teddifh or white. 
ptramdak. Ol a conchoidal texture, in a fingte 6-fided pyramid tranf' 
verfely ftriate. 
Senxerhy Brit. min. 2. tal. r02. 
Karjien Lejiic mineral. 1. p. >02, >03. 
1, With the pyramid perfeft. 
Born, ind. fofi. i. tab. 2. Jig. to. 
2, Witlt the pyramid truncate at top. 
Barn, ind, fofs, tab. 2. Jig. 2. 
3, With an additional b.fided pyramid at top. 
,4, With an additional 6-ftded pyramid at the top and the bafe. 
