482 University Geological Survey of Kansas. 
Mba )e UCR ae lay 8 ho alas 8 the) aeeay Ss fo, OLIN 8 fone s SbALR & 
(¢-, —2R) ) Po, +R). 
Medium-sized crystals of a deep amber color, from the 
Blaikie No. 2 mine. A typical crystal is shown in figure 45. 
The faces of 4- which occurs only on this type are dull and 
rough, and are characterized by etch-pits of a triangular or 
deltoid shape, as in figure 31. t: is striated parallel to its in- 
tersection edge with S-. K:, the dominant form, has its sur- 
face occupied by growth figures as exhibited in figure 46. 
The other forms are subordinate. Measurements as follows 
were used in the identification of the forms: 
No. of 
CRYSTAL. Angle. measure- Average. Calculated. 
ments. 
Ie aya OSS INSO Sia 6 80° 20’ 80° 46’ 
DB, || fete’ || QIB4Lp Bld 2 40 20 41 55 
Wo, & |) teats? | G1 B4p~319d. 1 21 00 20 864 
A || a@ope || O221 pOS87 3 15 05 14 48 
A | spo | O1IBp.OS87 5 29) 38 22. 09 
iar NOS Meg yqrlis Jeo jseliss OO sic sap cies) 320. 
Large amber-colored crystals from the ore body overlying 
the Roach cave in the western part of Joplin. Small, color- 
less crystals from the John Jackson mine, Chitwood hollow, 
Joplin, may also be referred to this type. On the single crys- 
tal (figure 47) obtained from Mr. James Roach, the basal 
plane is roughened by triangular etch-pits, and the faces of 
the unit rhombohedron p- are smooth and bright. The small, 
colorless crystals from the John Jackson mine have dull faces 
of the unit rhombohedron p-, while the basal plane o exists 
as a pseudo-face made up of minute projecting points with the 
faces of the unit rhombohedron. K: occasionally truncates 
the longer or obtuse polar ekge of K:,+R’. 
Type 11. O,OR; ¢.,—2R. 
Small, flat, colorless crystals from Aurora. g. is recognized 
by the fact that the cleavage rhombohedron truncates its polar 
edges. Figure 48. No measurements were made. 
