“NEW YORK MINERAL LOCALITIES 9 
_ Surface outcrops. The surface outcrops of rocks of all forma- 
tions but particularly unstratified rocks may be studied with 
considerable profit by the mineral collector in search of speci- 
mens. A judicious use of the hammer and cold chisel will often 
expose, under an unpromising cluster of weathered and decom- 
posed crystals, fresh material well worth the labor expended 
on its development. The precipitous faces of cliffs and escarp- 
ments, furnish in some cases profitable sources for the collection 
. of specimens. 
Drift boulders and fragments. While in some instances drift 
boulders, notably those composed of crystalline rock, are valuable 
sources of mineral specimens the uncertainty regarding the origi- 
nal locality from which they were derived tends to render ques- 
tionable the value of such specimens. A source of mineral ma- 
terial which may be classed under this head and which is often 
of more value than drift fragments embedded in the soil is the 
fragmental rock material used in the construction of stone walls. 
The accessibility of these to the roads and the comparative ease 
with which their component fragments may be identified with 
the country rock should not be overlooked by the collector par- 
ticularly in a region of crystalline schists. 
Natural caves. Subterranean tunnels and caverns, formed 
principally in limestones by the mechanical and chemical erosion 
of underground waters, frequently become repositories for secon- 
dary minerals deposited on the sides and roof as a result of the 
leaching action of percolating surface water. The exploration 
of these natural caves often results in the discovery of beautiful 
crystallizations which from the nature of their deposition are 
readily detachable. 
Mines and quarries. Probably nowhere is the mineral collector 
better repaid for his trouble than in exploring the dump heap 
of a mine. The waste material representing, as most of it does, 
the contents of the contact zone between the vein or ore body and 
the country rock is usually rich in ore minerals as well as in 
crystallizations of accessory minerals from the country roek. 
Similarly but to a somewhat less extent the rejected material 
from a granite or limestone quarry is a profitable collecting 
- source. 
