fenner: babingtonite from passaic county 601 



been supposed. Small remnants have been discovered on 

 nmnerous specimens (about two dozen in all have been obtained) 

 and its mode of occurrence is frequently such as to strengthen 

 the view regarding its relationship to the casts. In many in- 

 stances it is plain that the small fragments seen are survivals 

 of larger crystals. As a general rule the babingtonite is covered 

 with decomposition products, either the asbestos-like substance 

 mentioned in the preceding paper, or a green material, probably 

 of chloritic nature, or, less frequently, red hematite. In general 

 the greater part of the crystals has been removed and only the 

 impressions are left, but by directing a search among the termi- 

 nations of the cavities, where thin laminae of other minerals 

 projected into the original crystals, babingtonite has been found 

 so frequently as to leave little doubt that it represents portions 

 of the original crystals surviving because of their protected 

 situation. In another form of occurrence the relations are such 

 as to show that it is not of secondary deposition. Broad faces 

 of casts have been found, on which patches of babingtonite are 

 seen, and from other portions of the surfaces small projections 

 of the mineral run directly into the matrix. The relations indi- 

 cate that large crystals, which have been subsequently dissolved 

 away, carried small offshoots, which have been protected by the 

 matrix. The characteristics are those which have been ob- 

 served in several crystal groups of babingtonite which are in a 

 better state of preservation than usual. 



From a study of the specimens in which these relations have 

 been found it is possible to arrive at certain conclusions regard- 

 ing the nature of the casts which are due to babingtonite. 



In its simplest form the mineral has developed in small, thin 

 blades, extending Hke gashes into other minerals. These may 

 be single crystals or may form groups growing together without 

 apparent order. At times such groups show two or three crystals 

 of larger development, with small offshoots in various directions. 

 With increasing size the crystals, as inferred from the cavities, 

 have tended to assume rectangular forms, but with one dimension 

 still much less than 'the other two. In places the impressions 

 of these tabular crystals extend over a wide surface, often in a 



