SILICA. 
313 
blowpipe, or only at the thin edges, which are rounded, and become of a dark colour ; and it 
may by this character be distinguished from tremolitc, which it often resembles. This speci¬ 
men contains grains and crystals, which arc probably chromate of iron. 
The mineral called anthophyllite, from Rye in Westchester county, is probably tremolite; 
and the same remark will apply to that found at Smithtown on Long Island. 
In Massachusetts, according to Prof. Shepard, this mineral is found at Chesterfield and 
Blandford, associated with quartz in mica slate ; and in Connecticut, with tourmaline and 
iolite, at Haddam. 
HYDROUS ANTHOPHYLLITE. 
Hydrous Anthophyllite. Thomson. — (Formerly known by the name of Radiated or Stellated Asbestus.) 
Description. Colour white, greenish yellow or bluish grey. It occurs in plates, or very 
imperfect crystals diverging from various centres, or scopiform. The fibres are separable 
from each other, but more imperfectly than asbestus. Lustre silky. Opaque. Sectile, and 
has a soft feel. Hardness 2.5. Specific gravity 2.91. Infusible by the blowpipe. 
Composition. Silica 54.98, magnesia 13.38, peroxide of iron 9.83, protoxide of manga¬ 
nese 1.20, potash 6.80, alumina 1.56, water 11.45 {Thomson). 
LOCALITIES. 
Dutchess County. There is a locality of this mineral in the town of Fishkill, about five 
miles southeast of Stormville, on the land of Mr. Peck. It occurs in fibres forming radiated 
masses of a white and bluish grey colour, in a talcose rock. 
New-York County. Hydrous anthophyllite has been found in place on the west side of 
the island, between the 10th avenue and the Hudson, and between 57th-street on the south 
and 63d-street on the north. Here the strata are nearly vertical; the width of the bed at 
right angles to the strike, varying from three to thirty rods. Dr. Gale states that the granite 
lying on the west, and the gneiss on the east of the rock in question, come in complete con¬ 
tact with it without intermixing.* 
This mineral is also found in bowlders in various parts of the island. The fibres are some¬ 
times long and parallel; at others, short and radiated or interlaced. The true composition of 
this mineral was first pointed out by Dr. Thomson, who received his specimens from New- 
York. 
* New-York Geological Reports, 1839. 
Min. — Part II. 
40 
