i62 EARTHS. SILICEOUS. 55. Quartz urn. 



Found en barren commo-ns and heaths: is very ^afily blovrtl 

 about wli-en dry, biit when \vct is rather plailic ziid yields to 



■ the prc^ure of the hand, R is chiefly uCtd in the beds a«<i 

 moulds where metals arc call. 



f.sraria. In larger equal round traiifparent wbhiili grains. 

 Arena caarjpcJiris. Sj/i^aat, iii. 3. ^. 197, v. 4. 

 Arena quzrtzofa- fVaii. Jyst^ tnin, i , p. 103. ». 3. 



2. Arena niargaria. -Sj?/i, asc*. xii- 3. ^- 197. «, 5, 



Found on barren heaths and woody commons, and is priiici- 



paliy ufed in hour-glaffe^. 



\hi5u In very in mute round tranfparent while grains. 

 A, quartx. rottiii<i. diaph. hyal. Syji. not. xii. ». t, 

 A. qaartz mobiUiT, Wcdi.fjst. win. 1. p.ioit a-Si 

 Quickfand, S<hmei/s€r miner, J.^«336. 



1. A^qtiartz. vcTjto volatilis. Syfi^not. 1.^,5. 



2. A. quartz, rotund, acqual, 5y/?. »^j/. i. «. 4. 



3. A. quartz, impalpab. ■$//?. fi«?, \, p. 208. «• 2. 



FoUnd in the fea and adjacent waftes, and is alfd thrown oist 

 from ipring«: when dry it is fo light as to be driven «boiit by 

 the winds and collc^ed into fand -banks, and often taken up 

 in vaJi malTcs by whirlwinds, overwhelming and fufFocating 

 travellers and even whole villages: it is keptcompad by the 

 roots of the Elymus arenariu", Amrido arenarius, Triticum 

 repens, and fome fpfccics oi Willow. 



- 55* QUARTZUM. Confifling of fillca, about 6 



percent, of alumina, and i per cent, of carbo- 

 nate of lime: hard, lightlfh, brittle, (liining in- 

 ternally, breaking into indeterminate fragments 

 with acute margins, more commonly parafitical, 

 found in mountains of all ages, mouldering in 

 the air: not melting by fire alone, but with foda 

 running into a hard pellucid glafs. ^artz. 



Jihrosum, Diaphanous, whltifli, fibrous, with the fibres thicker and 



parallel, of a common form. 

 Bvrn- ifu^- fofu t./. zt. 2,/». 92. 



Fibrous Quartz, Kir^zvan mineral. I. />« 245. 'U/zr, ;;, 

 Found on the Carpathian mountains in Hunguryt and near Ra^ 

 bifchmi in Sikfia; exceeding rare. 



