EXAMINATION OP THE OCHROITES. £07 



XV. 



Chemical Examinntinn of the OchroiteSf a Mineral not hitherto 

 well knoii-n, containing a New Earth. By Klaproth *. 



JL HE foffil which forms the fubje£l of the prefent anal){is, Hiftoryof the 

 and to which I have given the name of ochroites, for reafons ' 

 to be dated hereafter, is found in the mine of Bafnaetes, near 

 Riddarhytta in Weftmannland. 



The firfl account of this mineral we owe to Cronftedt, who Fml noticed by 

 furniOied a defcription of it, together with that of another ^^""^^'^^i 

 mineral, found at Bifpberg in Delecarlien f . Scheele con- 

 (idered both as fpecies of iron ores, and gives to them the 

 name of lapis ponderofus, ponderous ftone, (fchwerftein) or 

 tungflen, which he defcribes in his mineralogy as terrinn 

 calciforme, terra quadem incognita intitne niixtum +. He like- ^"^ examined by 

 wife examined this tungften, and made us acquainted with 

 its true nature. The mineral which he examined, was, 

 however, the pearl-coloured tungften of Bifpberg, and from 

 this he concluded, that the examination of the tungften of 

 Riddarhytta was neceflary, confidering it a mineral of the 

 fame nature, he diftinguilhed it by the name of reddijh 

 tungfien. 



Soon afterwards D'Elhuyar analyfed both minerals, he and D'Elhuyar, 

 verified the analyfis of the true tungften, but proved that the 

 conje6lure of Scheele concerning the other mineral was 

 founded in error ; the refults of his analyfis ftiowed that the 

 foffil known by the name of reddilh tungften, was compofed 

 of 54 parts of lime, 24 of iron, and 22 filiceous earth. From 

 what follovvs, it will, however, become obvious, that this 

 mineral contains neither lime nor tungften, but a new earth 

 hitherto unknown. 



External CharaSiers of the Ochroites, 

 The colour of this mineral is between carmoifin red, clove- External cha. 



brown, and reddith-brown. It is compaft, breaks, fplinter- '■3*^^'"* "^ 



*^ ^ Ochroites. 



* Gehlen's new Journal of Chemiftry, Vol. II. part. iii. p. 303. 

 f Tranfaftions of the Swedifh Academy of Silences, 1751. p. 

 235. 

 X And alfo in Cronftedt's Mineralogy by Magellen, Vol. I. p. 46. 



ing 



