A. H. Chester—Mineralogical Notes. 285 
generally accompanied by small flakes of silvery mica, from 
‘which it is somewhat difficult to separate it for analysis. 
An analysis* of a pure sample resulted as follows: 
Cairns. Schafhautl. 
SHOR so eee eam amen eA UN AK 45-49 47-95 
NO a pe he Mc UI 31°08 34°45 
CaO ee ay BE eee Le 3°09 3°95 
Jd OSS 0 ls ca mt ra trace 1°80 
COU I Nae atk 2 tg ia et i Osailii 0°59 
lf Openimenisenise ge i 58 el 3°36 0°71 
KE OR eR IR Si ben 2S coe ty ot OG 10°75 
Na,O ene pee loc prey EAS, SEOUL ns Morte 2 () 0°37 
Vi) av Gele oh tae OA Wl A a Oe 0°35 
LE LG) iek os Ses SAC es aR Cae COTE SN 5°85 
Mo tale eye. ve sty) SSE OO OA 100°92 
An analysis of the Tyrol mineral is quoted for comparison. 
Another determination of the chromium gave 2°88 per cent of 
Cr,O,. The occurrence of chrome mica allied to fuchsite, at 
various places in Canada, has been mentioned by Dawson,t but 
I think no analysis has heretofore been published. 
The dolomite in which this mineral occurs is interesting, not 
only on that account, ‘but because of its peculiar appearance, 
its color, cleavage and crystalline characteristics, causing it to 
be readily mistaken for calcite. 
The analysist is as follows: 
(CEN ONG jects 2s a ere eee ni 52°83 per cent. 
JME CF Oi ie patie at aca eR I Rel 40°39)“ 
FeCO, -- cae Sea HED O TG Maae 
SVG area DA Neate ae me Picea WON HAD 1S 
EAE OE reese Shae Apes cheng te a OG OR Pimied 
OR TSIO) Ge ial ws te aes ae BE aC ase She 
1B 0 i ee es caer a Os Pa geincs 
EDO Calligaris oa 100°27 
This shows it to bea true dolomite in which part of the 
carbonate of magnesium is replaced by carbonate of iron. It 
is the common rock of the vicinity, but the fuchsite is found 
in it only at one place, on the eastern end of the island, the 
area containing the mineral measuring not more than thirty 
by fifty feet. 
* By Mr. F. I. Cairns. 
+ Geology of Canada for 1863, p. 494. 
¢ By Mr. William N. DeRegt. 
