Unwersittj of North. Dakota 



4(i — OrnaiiKMit. Mixlc from tltc S|>(';irf5s]i ov]»siim 1)v Mr. 

 Peter Thriiie. 



•45 — Plaster. Prepared from gypsum of tlie SpearKsb dis- 

 trict. 



Speartisli, Black Hills, Dakota. 

 II tltc S|>(';irf5s]i ov]»siim 1)y M 



8})carlish, Black Hills, Dakota. 

 47 — (TVpsuin, massive. 



Near Custer City, Black Hills, Dakota. 



4S — Gypsum, massive. 



Southwest of Custer City, Black Hills, Dakota. 



49-52 — Marble, variegated. 



Gilmau's quarries, near Sturi^is and Boulder Park, 

 Black Hills, Dakota. 



53 — Marble, variegated. Polished. 



Oilman's quarries, near Sturgis, Black Hills, Dakota. 



54 — ^Marble, variegated, polished. 



Oilman's (piarries, near Sturgis, Black Plills, Dakota. 



55 — ]V[arble, variegated, partially polished. 



Near Sturgis, Black Hills, Dakota. 



56 — Marble, white, polislied. 



Black Hills, Dakota. 



57-00 — Coal. Lignite. 



Near Hav Creek, noi't Invest ot" Speartish, Black 

 Hills, Dakota. 



07 OS — Grey building stone. C(>m|)act, siliceous limestone. 



Black Hills, Dakota. 



09 — ^^Red building stoiu'. 



lllack Hills, Dakota. 



7()-Sl — Mica, ot various colors; thin, ])road ])lates. Some of 

 these are (juite trans[»aient, and suitable for use in 

 stoves and hi'i terns. 



(lister district, J>lack Hills, Dakota. 



82 83— Mica. 



Ingersoll mine, Harney Peak District, l>lack Hills, 

 Dakota. 



