175 



analysis shows nearly the same amount of cerium and yttrium 

 earths. 



The type of apatite now described has been found only at 

 the locality No. 2 on Narsarsuk. The apatite crystals form 

 small crusts or druses on aegirine, epididymite , elpidite, etc. 

 t)ther minerals occurring at the locality and associated with 

 apatite are neptunite of type II, clear albite, parisite, cordylite, 

 polylithionite, etc. Of these minerals the apatite, no doubt, is 

 one of the vouneest. 



Type II. 



The apatite crystals of this type generally present a more 

 elongated prismatic form than those of the foregoing type. The 

 largest of them measure about 10"^°' in length and 1 "^^ in 

 thickness. As regards their development they are as simple as 

 those just described, the only forms present being the hexa- 

 gonal prism~ and the base. Sometimes on the edges of the 

 fundamental prism an extremely narrow truncation is observable 

 consisting of the prism of the second order. The faces in the 

 vertical zone are generally smooth and brilliant. Occasionally, 

 however, a feeble striation in vertical direction occurs. The 

 basal faces, on the contrary, are less even; they often have a 

 splintery appearance like a fracture. 



The crystals seldom form druses. They occur mostly as 

 isolated individuals implanted on larger aegirine crystals or 

 imbedded in a texture of aegirine needles. These crystals are 

 almost perfectly colourless and clear. Only an extremely faint 

 tinge of green is occasionally observable in them. On the 

 crystalline faces the mineral show's a marked vitreous lustre. 

 Owing to the scanty supply of material no complete analysis 

 has been made on this type of apatite. However, it has been 

 ascertained by quantitative tests that it contains rare earths 

 like the foregoing type. 



