108 



as to be essential ingredients. In the cases where more ana- 

 lyses of one mineral are found, the one has been chosen most 

 nearly corresponding to the average composition, or having 

 been made on the purest or most unaltered material. For 

 the sake of clearness, ingredients found in smaller amount 

 than V2 per ct., have not been included. Of the minerals 

 mentioned chalcolamprite and endeiolite have been mentioned 

 by Flink (Medd. om Grønland XXIV. pp.164, 169) britholite 

 by Winther (idem p. 195) steenstrupite and epistolite by Bøg- 

 gild (idem, pp.211, 188). For the other minerals the composi- 

 tion is given after Dana (Mineralogy 1892 and Appendix 1899). 



To avoid expressing any definite opinion of the mutual 

 relation of the minerals the above table has been arranged in 

 a quite formal manner, so that the silicates have been placed 

 first, the titanates next, and among these again the niobates 

 first, then the antimonates. The three carbonates dahllite, staf- 

 felite, and rivotite have been entered last; they are probably 

 only very distantly related with the others ; at all events it is 

 scarcely possible to tell anything more exact with regard to 

 their relation to other minerals upon the whole, as they are 

 quite wanting crystalline form. They are not included in the 

 following examination of the relationship of the minerals. 



A few other minerals might perhaps be added to the table, 

 as arrhenite and blomstrandite, which are, however, scarcely 

 proved to be independent species. Monazite, which is chiefly 

 a phosphate of the rare earths, contains generally, but not al- 

 ways, ca. 9 per ct. ThO^ and Г5 — 2 perct. SiO^ which may 

 together form a silicate of thorium ThSiO^ being perhaps pre- 

 sent as a mechanical admixture. Långbanite, which, after Flink, 

 contains 6VO2, Sb^Or,, MnO and FeO is shown by Sjögren 

 according to analyses by Mauzelius to contain the Sb as Sb^ O3. 

 Some niobates and phosphates , as annerödite and xenotime, 

 contain a small amount of tetravalent acids , probably not of 

 essential importance to the mineral, but a few silicates, as 



