EARTiiS. SILICEOUS. 54. Arena* i 6 t 
B. Compofed of comminuted quartoo. 
Gravel. 
Confining of angular unequal largers grains. 
Arena heterogenca. Syd. nat. xii, 3. p. 198. n. 9. 
Arena faxofa. Wall fst, min. l, p.^oh. n.q. 
Found every where on barren rocky mountains, and is produ- 
ced by granite which has mouldered front expofure to the 
air, and is frequently found mixed with particles of mica, 
felfpar and argil, it is principally afed for gravel walks, 
’^‘‘^oeea. Shining with numerous interfperfed fmall fcales of mica, 
refembling thin plates of gold or filver in colour and 
luflre. 
Arena micacea. Ka/. xii. 3 '/- 
Arena micacca- Wall. Jyst. min. l. p. lOJ- »»6, 
i. Arena CalTerita. aat. xii. 3. 198, ?r. 12. 
Found in Sweden and Germany, 2) in the iHand Cajferita, and 
is compofed of comminuted granite and other like ftones. It 
is the fand ufed to dry up the ink on newly written letters. 
'■''«««. Confifting of roundifli unequal larger grains. 
Arena heterogcnea. 6'vr/. nat. xii. 3./1. 197. n. 8. 
Arena quartzofa. Wall, miner 33. 
Common fand. Sckmeijfer mineral, I - 337 * 
Found every where in Europe, principally upon Ihores, and 
contains fome lamellar particles apparently of quartz, It is 
ufed for gravelling walks, 
In rounded minute feinitraufparent grains tinged with 
oxyde of iron. 
• Arena quartzofa, Syst. nat. xii. 3. p, 196. n. z. 
2. Arena ochracea. Syst. r.at. xii. 3. p. 197. n.q. 
3. Arena lacullris. Syjl. nat, xii. 3. p, 197. ». 3. 
Found in South America and Europe^ principally on the (hores ot 
lakes ; colour yellow, yellowifli, or tcftaceous, rarely red, 
violet in the Baltic near Germany. It is ufed for fprmkhng 
over letter.?, and makes admirable gravel walks. 
In very minute grains mixed with piilverifed alumina. 
Arena fubfarinacea. Syjt. ttat. xii. 3. p, 197. n, 6. 
Glarea parcic, inequal. Waller fyd, I. p 87. n, 2. 
2. Glarea fterilis fuforia. Wall. min. 
Glarea partic. fubtiiiff. W all, fyd. 1./. 86. ». 1. 
Dull fand. Grit. Schmeifserminer. p.^^b. 
VOL. VII, — X 
