80 NEW YORK STATE MUSEUM 
On a number of crystals repeated twinning according to this law was 
noted, in one instance as many as four repetitions of the twinning habit 
being observed [fig. 5]. The abnormal development of the basal plane pro- 
duces a tabular aspect quite characteristic of the occurrence. Some expres- 
sions of the twinning habit are shown in figures 3, 4, 5 and 6. 
Many of the crystals which were found lying loose on the floor of the 
innermost portion of the cavern were completely developed on all sides, 
showing no point of attachment. This fact which is sufficiently remarkable 
in crystals of this size may lead to some interesting speculations as to the 
manner of their production and the character of the crystallizing solution. 
Many of the largest crystals obtained from the outer cave were attached to 
the wall by a relatively small portion of their total surface so that it was 
possible to detach them by very little effort. 
One of the most striking characters of these crystals is a delicate 
amethystine to pink color shown on a large percentage of the specimens 
and which renders them singularly beautiful. The color appears to be 
irregularly distributed throughout the mass and shows deeper in the outer 
portions of the crystals. A tendency toward the concentration of color 
parallel to definite planes, notably the planes of cleavage, was noted. Cal- 
cite crystals similar in color have recently been found in the Maybell mine 
at North Empire, Kansas, and have been described by Sterrett,’ who notes 
a similar lack of uniformity in the distribution of color. A dendritic deposit 
of pyrolusite observed on the termination of some of the small crystals from 
the outer cave indicates the derivation of the color from a minute percent- 
age of manganese. 
Secondary aragonite occurs as an incrustation of minute acicular 
crystals on some of the calcite representing an early generation. Some 
quartz was noted associated with the calcite of this stage. Although con- 
siderable stalactitic calcite was observed coating the surface of the large 
crystals, very little evidence of true stalactitic formation was to be found 
1Sterrett, D.B. A new Type of Calcite from the Joplin Mining District. Am. Jour. 
Sci. 1904. 18: 73. 
