108 



in quite casual mutual positions. It is a characteristic fact 

 that the surfaces are originally almost always coated with a 

 thin, dust-like layer of a greenish or grayish colour, which is 

 seen under the microscope to consist of quite small needles 

 of aegirite, besides other irregularly formed bodies. The in- 

 terior of the crystals is also often penetrated by needles of 

 aegirite and other interpositions, by which means the crystals 

 become generally rather intransparent and of a light grayish or 

 greenish colour, even when the mentioned layer on the outside 

 has been rubbed away. It is especially on account of this 

 colour that the catapleiite described here gets an appearance 

 rather different from that previously known. 



Of accompanying minerals, besides aegirite, which is also 

 found in large crystals, only astrophyllite has been found, which 

 is sometimes sitting on the crystals of catapleiite as a loose 

 layer of felt, and sometimes also penetrates into them. Further 

 small crystals of rhodochrosite and albite^may be found together 

 with the catapleiite. 



The optical and other physical properties are in all essentials 

 as in the catapleiite of type I previously known ; they will be 

 more particularly mentioned hereafter. 



2. To this type belong some very small crystals (of a 

 diameter of up to 1 mm) ; they have only been found in a single 

 specimen, where they are sitting in cavities in aegirite and 



microcline together with a few 

 ^ — ГТ7ГХТ^1ТТГ^Г7777>^^^ crystals of albite ; they are not 



^--^ ^■■- If \ ^^-^:z^z::r^ accompanied by the catapleiite 



of the principal type. The 

 form is here made up of only 

 c{000l} and ^{ЮТЗ}, while 

 the prismatic surfaces are quite wanting (fig. 6). The surfaces 

 are very bright. As usually, c{000l} is the best developed 

 one and gives good reflections; г/{1013}, on the other hand, 

 is rounded and gives a continual series of reflections, which 



Fig. 5. Catapleiite, Type 4; 

 Narsarsuk. 



