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faces. The latter are, however, hardly ever quite even, but 

 almost constantly show a system of irregular elevations and 

 depressions. These are, however, of such small dimensions that 

 they can only be perceived with the aid of a magnifier. The 

 elevations then generally appear as very low, rounded wart-like 

 excrescences. Sometimes it looks as if the crystal had been 

 split up into a number of small irregular fragments, which had 

 been again cemented (or grown) together, not, however, quite 

 in their original position, but so that some portions rise above 

 the level of the others. 



In fact the chalcolamprite crystals are very often traversed 

 by open cracks, the separate parts being retained in their posi- 

 tion either by aegirine needles traversing the crystal across the 

 crack or by the attachment of the crystal. Sometimes the 

 crystals are hollow, consisting only of a thin shell of mineral 

 substance. One would be inclined to consider this hollowness 

 as secondary and due to some decomposition process in the 

 interior of the crystal. However, it is not probable that such 

 a process has taken place, for the crystal shell seems to be 

 quite as fresh and brilliant on the inside as on the outside. 

 Most likely it is that we have here an original skeleton structure 

 of the crystals. In the cavities there sometimes occur small 

 groups of aegirine needles arranged radially and having the 

 same lustre and characters as like needles outside the crystal 

 shell. 



The crystals mostly occur singly attached to their sub- 

 stratum. Not infrequently they are attached only by a corner 

 or an edge and. consequently, developed all around. In other 

 cases they are attached by an octahedral face , being flattened 

 [larallel to this face into thin triangular tables rising but little 

 above the surface on which they rest. Occasionally several 

 individuals are grown together, penetrating one another, always 

 irregularly. Twinning has not been observed. 



The mineral scratches apatite, but not feldspar. Its hard- 



