160 



which has the same yellow colour as the imfused mineral. 

 With salt of phosphorus a skeleton of silica is obtained, and 

 the bead is coloured by titanium. The mineral is not acted 

 upon by other acids than hydrofluoric acid. 



Narsarsukite has been found at the localities Nos. 1, 6, 7, 

 and 13 on Narsarsuk, consequently only in the southern part 

 of the mineral-bearing area. The largest quantity was collected 

 at the locality No. 1. It occurred here together with quartz, 

 microchne, albite, aegirine, graphite, elpidite, epididymite, and 

 the new mineral tainiolite. Narsarsukite is one of the earliest- 

 formed minerals at the place. Only aegirine seems to be 

 older, since needles of this mineral sometimes are found tra- 

 versing the narsarsukite tables. On the other hand, fully 

 developed narsarsukite crystals intrude into the individuals of 

 feldspar as луеИ as into those of quartz. The other accom- 

 panying minerals are still later formations than the last-mentioned. 

 However, the small cube shaped narsarsukite crystals are probably 

 of later formation, since they occur loosely implanted in open 

 spaces between the other minerals. The locality No. 6 did not 

 differ in any respect from No. 1 excepting that the mineral was 

 met with here in a far smaller quantity. At the locality No. 13 

 narsarsukite occurred as large, well-developed crystalline tables 

 firmly implanted in feldspar and quartz. They were not, how- 

 ever, quite fresh, but earthy on the surfaces and brown in 

 colour. At the locality No. 7 only a few loose specimens were 

 found, on which narsarsukite occurred associated with neptunite 

 of type III; it is, of course, older than that mineral. 



31. Chalcolamprite. 



As far as hitherto known, pyrochlore is a mineral which 

 occurs exclusively in syenite rocks. Thus the mineral was first 

 discovered in the syenite of southwestern Norway, where it is 

 met with in several places. In the Ihnen mountains near Miass 



