166 



However, this formula has no place for the combinations 

 RTiO.., EThO.^, etc. which are present in all natural pyro- . 

 chlores. 



Chalcolamprite has been found only at the locality INo. 7 

 on Narsarsuk. Only a scanty supply of the mineral could be 

 collected. As already mentioned, the chalcolamprite crystals 

 occur partly implanted on larger aegirine individuals, partly 

 attached to a network of thin needles of the same mineral. 

 Such fine aegirine needles often penetrate the chalcolamprite 

 crystals; they are, consequently, older than these. Chalco- 

 lamprite is, besides, accompanied by a large number of minerals 

 characteristic of this locality. Thus the brown zircon crystals 

 of type И occur here; they resemble the chalcolamprite crystals 

 very much in colour and size and, in some measure, also as 

 regards the crystalline form. Among the accompanying minerals 

 may, further, be mentioned albite in colourless crystals pris- 

 matically elongated in the direction of the vertical axis, and 

 ancylite, which is probably the youngest of the minerals occur- 

 ring at this locality. 



On a single small specimen from the locality No. 2 a couple 

 of small crystals are found which probably consist of chalco- 

 lamprite. They, however, differ from the usual chalcolamprite 

 in being bounded by eminently smooth and brilliant faces and 

 in lacking the metallic lustre which is otherwise characteristic 

 of the mineral; being brown in colour, like the other crystals, 

 they have the common vitreous lustre. These crystals occur 

 implanted on a well-developed, brilliant feldspar crystal. 



32. Eudeiolite. 



This new pyrochlore -mineral, has been named from the 

 Greek words sudsca, want, and Àllloç, stone, in allusion to 

 the fact that the analysis made on the mineral shows a con- 

 siderable loss. 



