332 DAVENPORT ACADEMY OF NATURAL SCIENCES. 



stone, and having a north-easterly strike, a small dip one way or the 

 other, and pitching along the strike. At Mount Hope there are five 

 nearly parallel beds in hard gneiss, but only two are of much import- 

 ance. The ore averages between 50 and 55 per cent iron, is hard and 

 uniform, but is mostly non-Bessemer owing to the presence of apatite. 

 The specimen is a fair average of the ore hoisted. 



Franklin Furnace, N. J. 



Franklinite — (^Fe Zn Mti) O, (^Fe Mii)2 O^ — variable. 

 Willemite — 2Zn O, Si O2. 

 Zincite — Zn O. 



Three specimens, showing different combinations of the above min- 

 erals. At Mine Hill, where the specimens were collected, the ore 

 bodies consist of two converging, nearly vertical beds or veins, in white 

 crystalline limestone overlying the archean gneiss. The ore consists 

 of varying proportions of the above minerals in a calcite gangue, the 

 specimen being richer than the average. It is first treated for zinc, 

 and the residue smelted for spiegeleisen. The region is very rich in 

 minerals and is remarkable as being the only place in the world where 

 the above minerals are of anything like economic importance. 



Hazelton, Penn. 



Two coal plants and specimen of pyrites from the anthracite col- 

 liery of Coxe Bros. & Co., at Oneida. 



ISHPEMiNG, Mich. 

 Hematite — Fes O^. 



Three specimens. Iron is found around Lake Superior in five ranges 

 or districts — Marquette, Menominee, Penokee-Gogebic, Vermilion 

 Lake, and Mesaba — all of which have many characteristics in com- 

 mon. Ishpeming is in the Marquette district. This is a very dis- 

 turbed region, and the geology and origin of the ore bodies have been 

 a subject of controversy. The ore is almost entirely hematite, but is 

 either soft and red or hard and specular, and occurs in various shapes 

 but commonly has a trough or basin shape. The geological section is 

 usually diorite, soapstone or jasper, ore, chert, quartzite. 



First specimen, "hard ore," or specular hematite, from the Lake 

 Superior Hard Ore mine. 



Second. Same from the Lake Superior Hematite mine. 



Third. Soft, red hematite from the Lake Superior Hematite mine. 



The first and third are average ores. 



Keweenaw Point, Michigan. 

 Specimen of Copper Ore . 



The copper in this region is entirely native — remarkably few cop- 

 per minerals being found. The copper-bearing horizon consists of 

 layers of igneous rocks and conglomerate beds dipping to the North- 



