iS A SYSTEI^ OF 
SECT. XL 
E. Cryflallifed calcareous fpars, Lapis calca^ 
reus cryftalUfatus, Spar Drufen 
It is compofed of the lall mentioned fpar 
(Se(5l.x.), that has formed itfelf exteriorly into 
feveral planes or fides, wherefrom many dif- 
ferent figures arife, the varieties of which 
have not yet been fully obferved, nor can they 
be exa(5lly defcribed. The following are there- 
fore mentioned, only as inftances of the 
moil regular and common kinds, viz. 
I. Tranfparent, Spatum druficim diaphanum. 
Hexagonal truncated, Cryftalli fpatoji 
hexagoni truncati. This is found at the 
Hartz in Germany, and at Jonufwando 
in Lapland. 
b. Pyramidal, Pyramidales, 
1. Dog’s-teeth, Pyramidales difitn^i. 
Found at Salberg, and in the iron 
mines at Dannemera in the province 
of Upland. 
2 . Balls of cryflallifed fpar, Pyrami- 
dales concreti -f . 
Thefe are balls which have Drufen, 
1 pyramidal, oftaedral, fpars accreted 
in their hollows ' or centers : they are 
found at Rettwin in the province of 
Dalarne, and other places 
* Tn my Ledures on Fofiils I have adopted this German 
term of Drufen into our Englifli language, for a duller of re- 
gular figured bodies, as a Groupe conveys the idea of a clufter 
only, whether regular or of indeterminate figures. D. C. 
t The concave figured fpar balls in the quarries of Somer- 
fctfhire, and other counties in England. Such bails of free- 
Hone are not unfrequently found. D. C. 
The name Spar is very well known, and only ufed to de- 
termine a certain figure, viz. when a flone breaks into a 
ihomboidal 
