137 



the crystals are often terminated in a number of points; occa- 

 sionally these end portions have an asbestos -like appearance. 

 Also here and tliere on the longitudinal faces of the crystals 

 considerable depressions have been formed by corrosion ; these 

 depressions are lined with needles and splinters lil^e those 

 occurring at the ends of the crystals. Between these fibres 

 of aegirine and often oriented parallel to them occur loren- 

 zenite crystals of type II. Elpidile crystals also occur in a 

 like manner, and it is evident that the two minerals have formed 

 simultaneously and during the decomposition process of the 

 aegirine. On the new-formed minerals there occur small curved 

 scales and basin -shaped crystal tables of polylithionite as the 

 latest formation. Also on small fresh aegirine crystals one finds 

 lorenzenite crystals in such a position that the two minerals have 

 their vertical axes parallel, while the first pinacoid of the former 

 mineral coincides with the second pinacoid of the latter. 



The later generation of aegirine consists of small green 

 translucent brilliant needles, the terminations of which are 

 also brilliant. Associated with this aegirine occur most of 

 the lorenzenite crystals of type I. The very brilliant needle- 

 shaped crystals of this type generally occur implanted in 

 irregular orientation on feldspar, where that mineral borders on 

 primary aegirine. Small secondary crystals of microcline, albite, 

 and epididymite are the usual companions of this type of loren- 

 zenite. These minerals are generally surrounded by a dark, earthy 

 substance, which is intensely soiling and probably owes its 

 origin to the decomposition of rhodochrosite, of which remains 

 are sometimes visible. 



28. Leucospheuite. 



The name of this new mineral is derived from the Greek 

 words Jsuxoç, white, and (т<р'^ы, a wedge, and chosen in allusion 

 to the white colour of the mineral and the wedge-like form of 

 the crystals. 



