No. 50.] 
109 
Silica, - 58.30 
Lime, 9.98 
Magnesia, - 24.22 
Protoxide of iron, 4. 24 
Oxide of manganese, 0.68 
Alumina, - 0.11 
Water, 3.11* 
The other varieties have a somewhat different composition. But 
they all serve to show how a mixture of pyroxene may impress its crys- 
talline character upon the steatite. We obtained numerous varieties of 
this substance, both in colour and structure, and it is probable that all 
these would exhibit some slight differences in chemical composition. 
Schiller spar, or metalloidal diallage. 
As there is some confusion in regard to the above names, it is proper 
to state that the mineral about to be noticed is identical with the schil- 
ler spar of Dr. Thomson.! 
Colour dark green, almost blackish green. Fracture uneven, splin- 
tery. Sectile. Specific gravity 2.746. It is in broad foliated masses 
which cleave in two directions, and apparently have the primary form of 
a rhombohedron. The lamina slightly curved. One of the cleavages 
is easily obtained and has a metallic pearly lustre, and a pinchback 
brown colour. Hardness about the same as that of serpentine. Pow- 
der yellowish grey. Where the mineral has been exposed to the air, 
it is of a tombac brown colour. 
Thin fragments treated by the blow pipe are merely rounded on the 
edges, but become of the same brown colour as when they have been 
long exposed to the air, and are attracted by the magnet. With borax 
it is fusible, though with difficulty, and the glass when cold has a green- 
ish colour. 
This mineral is found associated with dark coloured common ser- 
pentine at Brown's quarry, near Carmel, Putnam county. Its compo- 
sition is no doubt influenced by its contact with the latter substance. 
Allanite. 
This interesting mineral now for the first time, I believe, credited to 
the United States, has been found in Warwick, Orange county. The 
specimen which I received from Dr. Horton has the following cha- 
racters. 
Massive, although it has the appearance of being part of a crystal. 
Colour, brownish-black. Dull on the outside, but the fresh fracture 
has a resinous or imperfectly metalHc lustre. Powder brown. Opaque 
or feebly translucent, on thin edges. Very brittle. Fracture uneven 
or small conchoidal. Hardness about 6 . 0. Specific gravity 3 . 635. 
Before the blowpipe it melts with effervescence into a black shining 
glass. With borax it melts easily into a dark green glass. It gelati- 
nizes with heated muriatic acid. The solution causes an abundant pre- 
cipitate with ammonia. 
* Beudant, Traite Elementaire de Mineralogie, II. 224. 
t Outlines of Mineralogy and Chemical Analysis, I. 173. 
