82 NEW YORK STATE MUSEUM 
Most of the calcite specimens of types III, IV and V were obtained 
from a still larger vug which formerly extended across the ore body and was 
excavated previous to the writer’s visit. Much of the material collected 
from the dump heaps also showed evidence of the same vug formation. 
The several phases which mark the deposition of secondary calcite are 
characterized by calcite crystals of definite habit. Of these crystal types, 
the first two stand distinctly apart from a genetic point of view, whereas 
the last three are more or less closely related both from the standpoint of 
crystal genesis and habit. 
Type I [pl. 9, fig. 1-3]. Crystals of this type are found directly 
associated with the corroded quartz orthoclase and amphibole, in most 
instances deposited as a crust upon a highly corroded surface. They are 
distinctly scalenohedral in habit, the steep scalenohedron U:(5491) pre- 
dominating, modified in termination by the rhombohedrons m. (4041) and 
J.(0.13.13.4). Figures 1, 2 and 3 show this habit. The rhombohedron m. is 
present in a bright series of planes which furnished excellent points of 
reference. The rhombohedron J., on the other hand, gave faint but distinct 
reflections from a series of dull and somewhat rounded surfaces. On several 
specimens the rhombohedron p. (1011) is prominent in crystals of this habit. 
Several times during the measurement of crystals of this type, a narrow 
plane beveling the acute polar edges of U: (5491) was observed. A rhombo- 
hedron in this zone would have the indexes (0.13.13.2), a form which seems 
doubly probable in consideration of the fact that the presence of (0.13.13.4) 
has already been noted with reference to this type. No satisfactory reading 
could, however, be obtained. 
Crystals which measure from 3 millimeters to 25 millimeters in length 
are, in some instances filled with microscopic inclusions of quartz, hematite 
and matted byssolite, the latter forming a central nucleus of irregular shape, 
while the hematite, which was connected with a later stage of the crystal 
growth, appears in the outer layers in dendritic bunches. 
Regarding the generation of calcite of this type it must unquestionably 
be placed at the base of the calcite series as shown at Lyon Mountain. 
