56 
ECONOMICAL MINERALOGY. 
silica in many of its characters ; and when in considerable proportion, it is supposed to have 
an injurious effect upon the quality of the ore with which it is associated. In its pure or near¬ 
ly pure form, it is used for the purpose of giving a yellowish tint to artificial teeth; and in 
consequence of its comparative scarcity, and the difficulty of its separation from other sub¬ 
stances, is sold at a high price. 
Of the titaniate of iron in the crystalline form, and now known by the name of crichtonite, 
we have an interesting locality in Warwick in Orange county, where it is imbedded in a dark 
coloured serpentine ; and variable proportions of titanic acid are also contained in several of 
the iron ores of St. Lawrence, Jefferson and Orange counties. 
ORES OF ARSENIC. 
Arsenical pyrites, from which the compounds of arsenic used in the arts are obtained, has 
been found in this State, in the counties of Essex, Orange and Putnam. 
Essex County. Small veins of this mineral occur in the town of Lewis ; but the quantity 
which exists there, I have reason to believe, is quite inconsiderable. 
Orange County. There is a locality of arsenical minerals on the lands of Mr. B. Hop¬ 
kins, near the village of Edenville, which is particularly deserving of notice. Arsenical py¬ 
rites, composed of arsenic, sulphur and iron, occurs here in a vein in the white limestone. 
Associated with this is the arseniate of iron, or cube ore, as it is called from the primary form 
of its crystal, which here forms a coating to the preceding, and possesses a beautiful green 
colour and an adamantine lustre. Every where investing these two minerals is a powder of 
a lemon-yellow colour, which is ascertained to be the sulphuret of arsenic or native orpiment. 
In another part of the same vein is found a considerable quantity of the red oxide of iron, 
which, together with the sulphuret of arsenic, has undoubtedly been produced by the decom¬ 
position of the arsenical pyrites. And in addition to these metallic minerals, we have also 
arragonite in delicately radiated fibres, and of a snow-white colour, and occasionally thin la¬ 
minae of transparent sulphate of lime or selenitfe. On the whole, this is one of our most in¬ 
teresting localities, not only on account of the minerals which it affords, but of the apt illustra¬ 
tion which it presents of the changes produced in the mineral kingdom through the influence 
of chemical agencies. 
Putnam County. Near Brown’s quarry are two localities of arsenical pyrites, one of 
which has, at some former period, been extensively worked. The ore, which might be used 
for the extraction of arsenic, seems to be abundant; but the present condition of the mine 
renders it difficult to arrive at a certain conclusion on this subject. Its reported mixture with 
silver, is probably one of those stories circulated for selfish purposes ; and the only ground for 
it in the present instance, is the fact that in other countries the arsenical ores are often asso¬ 
ciated with those of a more valuable metal. 
