Prof. Berzelius on some nffvt locaUtki <>f rare Minerals SS'.i 



rock, particularly where the grain of the granite is larger. 

 The orthite so much resembles gadolinitc, that it was, at first, 

 ronsid.red as a variety of it, till Dr Wbhler, the first who ob- 

 served the orthite in the quarry of Skepsholm, found its che- 

 mical composition to he exactly the same as that of the orthite 

 from Gottliebsgang, at Finbo near Fahlun. Its fracture is 

 either glassy, or it is granular, and almost metallic, like that 

 of yttro-tantalite ; its colour is sometimes ycllowish-broun, and 

 even approaching to red, yet according to the experiments of 

 Dr ^VY., these, and the black varieties, do not present any es- 

 sential difference in their composition. The zircon is rather 

 rare. Generally the crystals, which are dark brown, are very 

 small, but some of them have been found half a line in diame- 

 ter, and two lines long. The soda-spodumene, the same min- 

 eral which I formerly (Aoffber. 1824. p. 16X>.) mentioned as a 

 new species found at Danvikgate, near Stockholm," met with 

 here in abundance, sometimes of a snow-white colour, and 

 distinguishable from felspar by its stronger lustre. The va- 

 riety from Skepsholm, has been analyzed by Mr Arfvedson, 

 who found its chemical composition to agree with the result I 

 had obtained last year. 



These minerals do not, in general, appear to be very rare 

 in the rocks in the vicinity of Stockholm, The soda-spodu- 

 mene U probably a very common mineral, but often mistaken 

 for felspar. I have Ken it in the granites of Norway. Or- 

 thite is found at Danvik, also in the Diurgard, (deer-park,) 

 and ahno-t in every place where rocks have be< n n< wly blast- 

 ed- I have seen a roundish mass in Skepsholmen of two 

 inches diameter. In a granite block, taken from a wall MM 

 Orkelliunga in Scania, I likewise discovered orthite, and Mr 

 Tank communicated to me large orthites from Lindisnaes, in 

 Norway, where they are found along with the phosphate of 

 yttria. These varieties have not yet been analyzed, but 

 their exterior appearance, and the characters which they ex- 

 hibit, when exposed to the action of the blow-pipe, w rery 

 nearly agree with those of orthite, that I do not doubt their 

 com}>osition will be found identical. 



A mineral, which seems to be l'yrorlhite, since it eotirel) 

 igreeswith it in its char when examined before the 



