PLATE VII 



Fig. I. Magnetite crystals nearly parallel in growth in a matrix of 

 hampdenite. The dodecahedron and cube ai'e prominent but 

 the surface is rough, and on two sides a great number of 

 minute octahedral facets are shown which suggests that the 

 entire crystal is built up of octahedra. 



Fig. II. Magnetite and hampshirite in hampdenite. The magnetite 

 shows a similar development of faces to Fig. L, but the octahe- 

 dron is more prominently developed than in the precedin,? 

 case and gives a striated appearance to the crystal and' at ont 

 place gives a nearly smooth octahedral face beveling the solid 

 angle of the dodecahedron. In both figures I and II the typi- 

 cal appearance of hampdenite is well shown. 



Fig. III. Cast of a hampshirite pseudomorph after humite. 



Figs. IV and V. Hampshirite pseudomorphs after humite showing typi- 

 cal development. Fig. V shows the best detached crystal 

 known to the author. 



Fig. VI. Group of Hampshirite pseudom^orphs after humite in hamp- 

 denite loaned by Prof, B. K. Emerson from the Smith College 

 collection. This is the specimen referred to on page 274. 



Fig. VII. Hampdenite showing smooth fibrous fracture. 

 Reduced one-halt 



