478 University Geological Survey of Kansas. 
Typsr 3 (Farrington). K:xXR*; w:,+3R’; (S-,—¢R). 
Small to medium-sized crystal from the Pelican mine, Jop- 
lin. ‘The faces of K: are smooth and lustrous, while those 
of w: are very rough and dull. They are represented in 
figure 36 (after Farrington). Measurements of the forms are 
as follows: 
CRYSTAL. Angle. measure- Average. Calculated. 
meuts 
wiAw:! | 83145,3415 2 46° 45’ Ae OY 
w:aw:Y| 8145,4185 2 16 45 16 QO 
Type 4 (Farrington). K:, +R*®; ¢, —2R; 4., —11R; 
S-, —¢R; z-, —#R, (D-, —iR) (0, oR). 
Colorless or amber crystals of small to medium size, though 
sometimes very large. The crystals studied by Farrington 
were from Leddy’s Lease, Central City, and he mentions 
them as a characteristic type for the Joplin district. Such, 
indeed, they are, for there is no type more widely distributed 
and so abundant as this one. ‘The writer has collected them 
from the following mines at Joplin: Portland, Bull Dog, 
Crystal Palace, Conqueror, Raspberry, John Jackson, Uno, 
Estrada, and Pelican; from the Homestake mine, at Granby, 
and from a mine at Duenweg. In the typical development 
of the crystals K:isthedominant form. ¢- is almost always 
rounded and cross-striated. 2%- appears as a pentagonal face 
with rounded surface and with its intersection edge with ¢ not 
sharply defined. =z often altogether lacking, is usually so in 
one or two of its faces. A typical crystal is represented in 
figure 37. On acrystal from an unknown locality in Joplin 
the forms D- and o occur. Although K: usually is the domi- 
nant form, sometimes ¢- assumes that role, the faces of the 
former not being present at all. A few such crystals were 
found at the Homestake mine, Granby, and Duenweg along 
with those of normal development. Crystals of this type from 
the Pelican mine, much shortened in the direction of the 
vertical axis, have as the dominant form S- represented in 
figure 388. Such variations, though perhaps present more or 
