73 



porous masses, which fill the spaces between the primary 

 minerals. These aegirine crystals are only a few mm. in length. 

 The terminal faces of these crystals are bright, but uneven and 

 allow of no accurate measurements. 



In the porous masses of elpidite from the locality No. 2, 

 in which the leucosphenite was found, numerous aegirine crys- 

 tals were imbedded. These crystals, which sometimes have the 

 thickness of a finger, are evidently older than the minerals in 

 which they occur imbedded. In the vertical zone occur the 

 usual forms ш, a, b with brilliant faces. Towards the ends the 

 crystals present a quadrilateral tapering caused by the vicinal 

 faces X etc. on one side and, possibly, =^ {66l) on the other. 

 These four planes do not, however, run out in a point, the 

 crystals being, as it were, irregularly broken off at the ends 

 and terminated by a number of spUnters (Fig. 5, Plate IV). 



It looks as if these aegirine crystals were not originally 

 formed in situ, or at least not in the position in which 

 they are now found. They are often developed at both ends 

 and are never implanted on larger mineral individuals. Some- 

 times they are broken into pieces and the parts of the broken 

 crystal are found near one another, but separated by elpidite 

 needles that have intruded between them. That the formation 

 of the porous mass has not taken place without disturbances, 

 may be inferred from the fact that the elpidite needles them- 

 selves are broken, the relative position of the fragments exhi- 

 biting the greatest variety. The cement by which the present 

 position of the fragments is tolerably well secured is calcite 

 crystalUzed out, too sparingly, however, by far to fill up all the 

 interspaces. 



The locality No. 1 is characterized by the presence of 

 quartz as crystals rather rich in faces and of narsarsukite and 

 tainioUte. The aegirine occurring here is also of a peculiar 

 character in certain respects. The crystals are rather small 

 and often traversed by brownish yellow zones and spots. Thèse 



