Cooper & Stanley (1990) states:
A roughly N-S vein appears to have been tried near the head of the gill [NY307324]. The vein is predominantly of a hard gossany nature with spongy quartz impregnated with iron and manganese oxides. The locality is well known as a source of good, though small, crystals of pharmacosiderite. Several other arsenates and phosphates occur here and the locality has received a good deal of attention from collectors.
