452 J. D. Dana on Serpentine Pseudomorphs 
same difference,” 
(5.) Conclusions.—The following conclusions flow from the 
facts that have been stated. 
e original mineral was crystallized in tabular rectangu- 
lar forms, and, as the striez and angles show, was orthorhombic. 
2. The tabular crystals were half an inch and less in thick- 
ness, and probably were imbedded in an uncrystallized mass o 
the same composition. 
3. Cleavage was very easy parallel to one of the planes, the 
basal plane of fig. 9, and much less so parallel to one or both o 
the others; and as the subdivision into blocks or plates by 
pseudomorphism shows, there were many cleavage-joints. 
4. The color was dark green or greenish black; but perhaps 
paler on the basal plane. 
5. The crystals had considerable luster, some still remaining 
] 
: 
; 
r. 
tine pseudomorphs of the Tilly Foster Iron Mine are never 
dark green, except when the original mineral contained con- 
n. 
bands show. The air-cells are in the white serpentine and not 
or carbonic acid was the gas that escaped. 
fF a 3 
_ May have been due to the escaping gas alluded to, swelling 
up the white serpentine. 
