262 Account of some new Vesuvian Minerals. 
posed to a strong heat, acquire a beautiful blue colour, with- 
out melting. 
When pulverised and exposed, in a platina crucible, to red 
heat there is no loss. 
The sulphuric, nitric, or idiocloric acids partially dissolve it, 
and the solution gives with ammonia, a precipitate, whic 
with cobalt before the blowpipe, becomes blue. The liquid 
deprived of = ote among gives with oxalic acid, a precipi- 
tate of brown 
Sulphuric acid ae in a singular way on the Christianite, 
altering very considerably the bulk, and converting it into an 
imperfect vesicular jelly. To obtain this result, it should be 
fmely pulverised and washed in sul. acid, with its own 
weight of water. 
‘arieties. 1. Quadri-decimal—(fig. 203)* 2. Octo- 
decimal—(fig. 204.) 3. Regular doles aliedctaeniilie 205.) 
a. Dodecahedral elodsicanibeasdin 206.) 4. Dioctahe- 
drakes-(fig 207. — 5. oar 208.) 6. 
Blunted—(fig. 209.) 7. Defective—(fig. 210.)+ 8. Bis- 
duodecimal— (6g 211.)t 9, Feraliedosl 4 Christaaiee ry 
5 eb 
aN Crestianite 
’ 208. 
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7 
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* For this aoe: see the precedi 
__t Fer the se figures, se e the cucatine grea; < . 265: 
