74 NEW YORK STATE MUSEUM 
SOMERVILLE, ST LAWRENCE CO. 
Plate 7, figures 1-7 
These calcite crystals were collected from the workings of the Caledonia 
mine about 1 mile east of Somerville, St Lawrence co. The crystals of type 
V occur associated with hematite on two specimens collected by Mr D. H. 
Newland. For a fine crystal of type II the writer is indebted to Mr 
Thomas Cameron. A small series furnishing types I, II, III] and IV were 
collected by Mr R. S. Hodge of Antwerp. 
Type I [fig. 1]. Crystals of type I occur deposited on a thin layer of 
crystallized pyrite lining cavities in the pinkish crystalline limestone of the 
wall rock. They are rhombohedral in habit, the dominant forms being 
the fundamental rhombohedron p.(1911) and the negative rhombohedron 
8.(0112). Small bright planes of the prism b.(1010) are present in the 
rhombohedral zone. The lateral edges of p. are modified by brilliant but 
somewhat rounded planes of the rare second order pyramid 7(5.5.10.1), 
described by Rogers on the calcite from Frizington, England,’ and by 
extremely narrow, bright planes of the positive scalenohedrons K: (2131) 
and N: (5382) in the zone [1011.1120]. 
Type II [fig. 2]. This type was observed on a single specimen con- 
sisting of one large crystal which measured 45 millimeters in vertical hight, 
and a number of small attached crystals, and on two specimens of the 
series collected by Mr Hodge. These crystals are evidently of a second 
stage of generation derived from a previous rhombohedral type which latter 
appears as a phantom outlined by minute inclusions of pyrite. The presence 
of phantom crystals of rhombohedral habit appears to indicate the for- 
mation of the crystals of type II around a preexisting individual of type I. 
Crystals of this type show prominent development of the planes of a new 
pyramid of the second order ¢(8.8.16.1). This pyramid, which is the 
most acute yet observed for calcite, is well defined and corresponds well 
with previously recorded forms, supplying another member to the series 
2P2(1121), 4P2(2241) and 8P2(4481). The relation of the new pyramid 
Rogers, A; EF. Am: Jour. Sci. 1901, yi2244; 
