16 Bulletin of the New York State Museum. 



of the others. Though never found in perfect crystals, it is yet per- 

 fectly crystalline. In color it is a light straw yellow. It can often 

 be cleaved in perfect rhombs from one to five inches across the face. 

 On every rhomb, striae run diagonally across the faces, indicating the 

 fact that, as usual, the mass is twinned, not simple. In fact, many 

 times the mass will part parallel to these twinning strise rather than 

 to the prism faces. 



The appearance of the mineral is also much modified by its asso- 

 ciations. Whenever enclosing another mineral, the cleavage surfaces 

 always present a warped appearance. This warping varies directly 

 with the size and number as well as with the variety of the mineral en- 

 closed. In the first case, suppose the enclosed mineral, say a crystal 

 of pyroxene, be very small : then the warping would be noticed with 

 difficulty, if at all, whereas if the. size of the crystal were increased 

 the warping would extend over a surface of two or more inches 

 across, with a departure from a straight line, at that distance, of 

 nearly one-fourth of an inch. 



In addition to the warping there will also be noticed a granulation 

 extending various distances from the surface of the crystal. These 

 granulations are nothing but smaller crystalline masses surround- 

 ing the enclosed mineral, which, for some reason, have not been 

 free to assume the more coarsely crystalline state. This peculiar 

 aggregation conforms closely to the shape of the enclosed crystals, 

 though, as it reaches away from the enclosure, the angularity is lost. 

 Unfortunately there was no opportunity to test this peculiarity in 

 connection with the largest crystals, since they were wholly free from 

 the calcite. If, however, the bulk of the surrounding calcite was 

 not proportionate to the size of the crystals, the warping must have 

 been very great. 



Thus far the facts of occurrence, of these minerals as well as those 

 from Nevvcoinb, alone have been stated. The question now arises, do 

 these facts warrant any other explanation than that of the fusion 

 theory ? It is difficult to understand how either dry, or aqueous 

 fusion could have produced these results. In both cases it would 

 seem that in cooling slowly they would have assumed their original 

 form, if, indeed, we could safely assume a perfect form oiigiiially. This 

 explanation is too complex, when a simpler one is at hand, which ap- 

 pears to answer every purpose. The explanation by the assumption 

 of a partial solution appears to involve even greater difficulties. For, 

 while there is no doubt that a sufficient degree of heat could be 



