134 NEW YORK STATE MUSEUM 
Both Rhisnes and Andreasberg lie in the horizon of the Devonic and 
Upper Carbonic rocks and present the phase of subordinate beds of lime- 
stone overlaid by graywacke, clay slate, silicious slate and quartzite. In 
the vicinity of Andreasberg, these strata are frequently broken through by 
granite masses.’ These conditions show a marked analogy to those existing 
at Union Springs and at Fayetteville, where the limestone beds are overlaid 
by the shale and silicious slate of the Marcellus and Hamilton groups and 
show evidences of considerable local disturbance. The limestone on which 
the Union Springs pyramidal calcite crystals are deposited is unique in 
that the silicious residue obtained from its solution consists of minute but 
perfectly formed quartz crystals. As pointed out by Penfield and Ford? 
pyramidal crystals of calcite, of the form (8.8.16.3) and containing nearly 
50 % quartz sand, have been found in the Bad Lands of South Dakota. It 
would therefore appear that in at least two localities producing the pyramid 
y asacrystal habit, the occurrence is marked by the presence of silica under 
rather unusual circumstances. When we add to this fact the equally sig- 
nificant one that the formation at Union Springs and Fayetteville and at 
the Belgium and Hartz localities show in each instance disturbed limestone 
beds overlaid by strata rich in silica, we would seem to have reason for con- 
necting the pyramidal habit of calcite with a crystallizing solution carrying 
silica in quantities approaching saturation. 
Applying this theory to the occurrence at Lyon Mountain, the con- 
clusions drawn from the Union Springs occurrence, where a single pyramid 
7 (8.8.16.3) was used as a basis of comparison between the Union Springs 
calcite and that from Rhisnes and Andreasberg, gain added force in 
the case of Lyon Mountain, where a series of five pyramids occur in the 
various types, four of which pyramids are found on the Rhisnes calcites 
and three of which also occur on the Andreasberg crystals. The dominant 
1 Phillips, J. A. & Louis, Henry. A Treatise on Ore Deposits. 1896. p. 384. 
? Penfield, S. L. & Ford, W. E. Silicious Calcites from the Bad Lands, Washington 
Countyson Dee eats) Otte OCl pL O00 me Qeaoz: 
