So A SYSTEM OF 
SECT. LXXIL 
2- Cockle or Shirl, Bafaltts\ Corneus cryftaU 
lijatus Wallerii ; Stannum cryftallis coliimnari- 
, hus nigris Linnai, 
Is a heavy and hard kind of ftone, which ' 
fhoots into cryilals of a prifmatical figure, 
and whofe chief colours are black or green. 
Its fpecific gravity is the fame as the garnets, 
viz. between 3000 and 3400, though al- 
ways proportionable to their different foli- 
dity. 
A, Cockle, or fliirl, mixed with iron, Bafaltes 
martialis. 
r. Coarfe, without any determined figure, 
■ Bafaltes particulis palpabilibus figura in^ 
determinata, 
a. Green, found in moil of the Swedifh 
iron mines. 
by exp?ofing it to a heat augmented by degrees, becaufe then 
the tin and lead fvveat out in form of drops, almoft pure, 
though always fomewliat mixed with iron. 
The criftallifations of the garnets are fo far dilFerent from 
one another, that feme have a greater and fome a lefs num- 
ber of facets, or fides ; but this has no relation or dependence 
either on their contained metals, their colour, or their 
tranfparency ; wherefore, in order to avoid a prolixity, 
which is unnecefTary, I have omitted fuch varieties, and only 
obferved that they are round or fpherical, with facets. Be- 
fides, there is not yet difeovered any figure amongft them 
which is abfolutely particular and remarkable, for the 
granatus dodecaedros ex rhomhis Lbinai are difperfed every 
where in the rocks at Kongsberg, in Norway. 
SECT. 
