524 BARON A. E. NORDENSKIOLD ON THE OCCURRENCE [Aug. I9OO,. 



by means of spectrum analysis by Thalen, after whom the mineral 

 has been named thalenite. 



The other mineral, kainosite, was discovered by me in 1886 on 

 examining a large collection of fine specimens of gadolinite from 

 Hittero. It is a silicate-carbonate of yttrium and calcium ; con- 

 sequently, as the name also indicates, of a rather uncommon com- 

 position. What induces me to mention it in this place is the 

 circumstance that the same mineral has since (in 1896) been found 

 by Dr. Gr. Mink and Prof. H. Sjogren in the form of small, though 

 well-developed crystals in the nucan clays and on the walls of the 

 fissures and drusy cavities at the Nordmarken Mines. I had pre- 

 viously observed that the clay, which partly fills the drusy cavities 

 and fissures there, contains small detached crystals of a great number 

 of recently-formed minerals, different in different fissures. Thus, 

 for instance, fine, sharply defined, quite uncorroded crystals of 

 augite, garnet, epidote, titanite, calcite, and pholidolite may be 

 obtained by washing from the clay of one fissure ; crystals of apo- 

 phyllite and amphibole from that of another ; crystals of pyro- 

 smaltite, amphibole, and magnetite from a third ; and so on. 



All these minerals, though occurring in our oldest rocks, are 

 recent formations — geologically speaking, children of the latest birth. 

 Their mode of occurrence, in veins which are in course of formation- 

 in our older rocks, suggest speculations of wide scope with regard 

 to the origin of a certain kind of pegmatite-veins. In the vicinity 

 of Arendal I have seen a fissure like those just mentioned filled 

 with clay enclosing large crystals of quartz, mica, and felspar,, 

 evidently of recent formation, running alongside a pegmatite-vein 

 rich in minerals containing rare earths. Large lenticular masses 

 of a cerium-mineral, allanite, occur along the lode at the iron- 

 mines of Gyttorp, near Nora. These mines are, next to the Bastnas 

 Mines, the richest in cerium-ore hitherto known. On the other 

 hand, no real yttria-minerals, except the kainosite just mentioned, 

 have been met with in the fissures alongside our iron-ore lodes. 

 The occurrence of the unimportant yttria-mineral in the fissure-clay 

 at Nordinarken, and the occurrence of allanite at Gyttorp, indicate 

 that the mode of formation of newly originated fissure-minerals in 

 our mines and that of the pegmatite-veins in our older rocks do not 

 differ so much as is generally supposed. 



During the century that has elapsed since the discovery of y ttria, 

 anumber of new elements have been separated out of this earth, which 

 were at first presumed to constitute the oxide of a single element. 

 Thus, in 1842, erbium and terbium were obtained by Mosander; then, 

 chiefly by Marignac, Cleve, and Nilsson, with the aid of spectrum- 

 analysis, thulium, holmium, scandium, ytterbium, demonium, etc. : 

 in a word, a comparatively large number of the seventy or more 

 elementary bodies of which all known matter consists. However, 

 none of these new substances have as yet been utilized in the arts, 

 and many persons will, therefore, probably consider the results 



