THE PROPERTIES OF MINERALS. GG9 



Combination of the octahedron, cube, and dodecahedron : Cuprite, Cornwall, Euglaiul. 

 (Cat. No. 50131', U.S.N.M.) 



The tetrahedron : Tetraliedrite, Kapuik, Hungary. (Cat. No. 48653, U.S.N.M.) 



Combination of the p/».s' and minus tetrahcdron.s : Tetraliedrite, Kapnik, Hungary. 

 (Cat. No. 48653, U.S.N.M.) 



Combination of the cube, dodecahedron, and the plus and minus tetrahedrons : Horacite, 

 Luueuberg, Germany. (Cat. No. 45679, U.S.N.M.) 



The pentagonal dodecahedron : Cobaltite, Tuuaberg, Sweden (Cat. No. 49003, 

 U.S.N.M.); pyrite, Saratoga mine, Central, Colorado (Cat. No. 48557, U.S.N.M.). 



Combination of the pentagonal dodecahedron, diploid, and octahedron : Pyrite, Kongs- 

 berg, Norway. (Cat. No. 13116, U.S.N.M.) 



Combination of the diploid, cube, and pentagonal dodecahedron : Pyrite, Bros.so, Pied- 

 mont, Italy. (Cat. No. 51881, U.S.N.M.) 



Tetragonal st/sfem. — Lateral axes equal, the vertical a varying axis. 

 Includes all forms referable to one principal, or vertical, axis which ia 

 peri)endicular to, and different in length from, the lateral axes. The 

 two lateral axes intersect each other and the vertical axis at angles 

 of 90 degrees. 



Exa7nples. 



The pyramid: Scheelite, Sclilackenwald, Bohemia (Cat. No. 84122, U.S.N.M.); 

 octahedrite, Pardatscb, Tavetschthal, Switzerland (Cat. No. 81464, U.S.N.M.). 



The prism : Apopbyllite, Cape D'Or, Minas Basin, Nova Scotia. (Cat. No. 83416, 

 U.S.N.M.) 



Combination of the pyramid, prism, and basal plane: Vesuvianite, Italian Peak, 

 Gunnison County, Colorado. (Cat. No. 82124, U.S.N.M.) 



Combination of the pxjramid and prism: Thorite, Arendal, Norway (Cat. No. 84130, 

 U.S.N.M.); rutile. Graves Mountain, Lincoln County, Georgia (Cat. No. 84099, 

 U.S.N.M.). 



Combination of the prism and pyramid: Zircon, Natural Bridge, Lewis County, 

 New York. (Cat. No. 81654, U.S.N.M.) 



Combination of the pyramid and two prisms: Wernerite, Pierrepout, St. Lawrence 

 County, New York. (Cat. No. 14314, U.S.N.M.) 



Hexagonal system, — Axes four. The three lateral axes equal, inter- 

 secting the principal, or vertical axis, at angles of 90 degrees, and each 

 other at angles of 60 degrees. The vertical axis of a variable length. 



Examples. 



The pyramid: Quartz, Amelia Courthouse, Virginia (Cat. No. 47958, U.S.N.M.); 

 corundum, Ceylon (Cat. No. 83030, U.S.N.M.). 



Til e prism: Pyromorphite, Little Giant mine, Shoshone County, Idaho (Cat. No. 

 48590, U.S.N.M.); beryl, Leiper'>s quarry, Chester, Pennsylvania (Cat. No. 50642, 

 U.S.N.M.). 



Combination of the pyramid and prism : Quartz, Warstein, Germany. (Cat. No. 

 81409, U.S.N.M.) 



Combination of the prism and pyramid: Beryl, Stony Point, Alexander County, 

 North Carolina. (Cat. No. 82837, U.S.N.M.) 



Combination of the prism, pyramid, and base: Apatite, Renfrew County, Canada. 

 (Cat. No. 82365, U.S.N.M.) 



The rhomhohedron : Chabazite, Was.son8 Bluff, Minas Basin, Nova Scotia (Cat. 

 No. 81.347, U.S.N.M.); rhodochrositc, John Reed mine, Alicante, Lake County, 

 Colorado (Cat. No. 84128, U.S.N.M.); calcite, England (Cat. No. 83376, U.S.N.M.). 



The scalenohedron : Calcite, Oswego Land, Jopliu, Missouri. (Cat. No. 81778, 

 U.S.N.M.) 



