10 CataJ Of/lie of Dfuseimis. 



V ; 134 — Hornbk'iiile Rock, with imbedded crystals of Iron py- 

 rites. 

 s^ . Black Hills, Dakota. 



185— xVsbestos. 



Black Flills, Dakota. 



186— Dog-tooth Spar. Variety of Calcite. Large slab of 

 -^'^ crystals, yellowish in color. 



Black Hills, Dakota. 



187 — Dog-tooth Spar. Variety of Calcite, aggregation 

 somewhat different from the preceding. White and 

 .. . passing to the glassy and almost colorless. 



. ■. Black Hills, Dakota. 



, ]-'8 — Dogtooth Spar. Aggregation of crystals, differing 

 from the foregoing. Color bnff to reddish. 



Spring Creek, Black Hillfe, Dakota. 



189 — Nail-headed Spai-. Variety of Calcite. Aggregation 

 of "nail-headed" crystals. Yellowish in color. 



Black Hills, Dakota. 



140 — Nail-headed Spar. Aggregation of "nail-headtd" crys- 

 tals. White in color. 



Black Hills, Dakota. 



141-1.52 — Calcite crystals. Large crystals from the roof and 

 walls of Whitewood Cave, six miles northeast of 

 , : Dead wood. 



Black Hills, Dakota. 



158-155 — Red and White Lime Rock, showing concentric rings 

 of color. 



Lead City, Black Hills, Dakota. 



156-158 — Columbite. Crystals. Large and fine. 



Harney Peak region. Black Hills, Dakota. 

 159 — Banded Sandstone. 



Near Deadwood, Dakota. 

 160 — Geode and vug. 



Black Hills, Dakota. 



161— Utica Shale, with Trilobite impressions. 



Custer City, Black Hills, Dakota. 



162 — Concretion. 



Black Hills, Dakota. 



