MINERALS AND GEOLOGY OF CANADA. 531 
. forms, when polished, a handsome (though opaque) stone, fit for rings 
and brooches. In some directions, a slight chatoyance is observable. 
Datolite.—Chiefly pale green or colourless, in botryoidal and 
fibrous masses, and in monoclinic crystals. H. 5-0-5°5; sp. gr. 2°95- 
3°0. Fusible with bubbling ; imparting a greenish tint to the flame ; 
and yielding in the bulb-tube about 5 or 6 per cent. of water. Com- 
position : silica, boracic acid, lime, and water. Occurs with prehnite, 
laumonite, &c., in association with the traps of the north shores of 
Lakes Huron and Superior. Fine crystals are found at Isle Royale, 
and on the south shore of Lake Superior, in the copper region. 
Thomsonite.—Chiefly in white or light-coloured acicular crystals 
and fibrous masses, in (or connected with) the traps of Lakes Huron 
and Superior. H.5:0-5°5; sp. gr. 2:°3-2°4. Fusible, with previous in- 
tumescence. If free from weathering, in which case it will be trans- 
lucent, it yields about 13 per cent. of water in the bulb-tube. Compo- 
sition: silica, alumina, lime, soda, and water. 
Analeime.—Chiefly in trapezohedrons (fig. 45,) of 
a white or greyish colour, associated with the traps 
of Michipicoten Island and the shores of Lakes Huron 
and Superior. H. 5:0-5:5; sp. gr. 2:0-2°1. Fusible 
quietly, id est, without imtumescence or bubbling. 
Yields in the bulb-tube from 8 to 9 per cent. of water. OEE 
Composition: essentially, silica, alumina, soda, water. 
Apophyllite.—In lamellar masses and dimetric pyramidal crystals 
of a white or light colour, with pearly opalescence on the top or basal 
plane. H. 4:5-5°0; sp. gr. 2:32-2:37. Exfoliates before the blow- 
pipe and fuses with bubbling. Inthe bulb-tube, yields about 16 per 
cent. of water. Composition: silica, lime, potash, and water. Found 
here and there in connection with the traps of Lakes Huron and 
Superior. Fine crystals come from the copper region of the south 
shore of the latter lake. Thomsonite, apophyllite, and other “ zeoli- 
tic’ minerals, occur also, it may be observed, both abundantly and in 
fine examples, in the trap rocks of Nova Scotia. These are sometimes 
red, greenish, &c., as well as colourless. 
[Wilsonite—Altered Scapolite——In columnar masses of a peach- 
blossom-red colour, from Lanark County, C. W. See under “ Scapo-. 
lite,” C 3, above. 
(To be continued. ) 
Vou. V. 2P 
