three Minerals from Lake Superior. 489 
With nitrate of cobalt it gives a beautiful blue. 
It is readily dissolved by chlorohydric acid, the silica being 
entirely separated in the form of a flocky precipitate. 
The analysis gave 
Oxygen. Ratio. 
Silica 36.99 19.22 . 3.00 
Alumina 25.49 
Peroxide of iron and a little Fe 6.48 13.90 2.10 
im 19.90 
Soda 3.70 6.50 1.01 
Potash .40 
Water 1.99 6.40 -1.00 
100.18 
The ratio of the oxygen of H, R, E and Si; being 
1:1:92 : 8, the formula will be 
Ca? we: Al see B 
x. bs + 2 2 Si + 3H 
This formula would be that of Meionite with the addition 
of three atoms of water. A small portion of the iron exists 
in the mineral as protoxide, so that the analysis gives a slight 
excess of the bases R. 
This mineral was named by Dr. Jackson, in allusion to its 
Peculiar stellated structure and greenish color. It receives a 
fine polish, and would form beautiful ornaments for setting in 
jewelry could it be found in quantity sufficient for that pur- 
Nore. The Wollastonite and Jacksonite were first ob- 
tained by Dr. Jackson and myself at the Cliff mine, in the 
Summer of 1845. The analyses of the former were made in 
the laboratory of Prof. H. Rose in Berlin. The specimen of 
acksonite which was analyzed was from Isle Royale. 
