Geology and Natural History. 23& 



ganbrucite occurs at the manganese mines of the Jakobsberg 

 together with hausmannite, jakobsite, piedmontite, manganophyl- 

 li" , hraunite, etc. It is found in granular form, of the size of 

 ' the hausmannite ore, consisting of hausmannite 



less thickly imbedded in calcite. 

 ; color from honey-yellow to bro 

 ally marly colorless; translucent in thin splinters. 



MsrO 



color from honey-yellow to brownish-red, perhaps 

 riginally nearly colorless ; translucent in thin splinters. An 

 nalysis gave, after deducting a very little silica and calcite : 



This corresponds approximately to the formula (Mg,Mn) H a O s , 

 or a mangnnesiari variety of brucite. 



Talktriplite is from Ilorrsjoherg in Wermland, where it 

 occurs will J te which it much resembles, and 



other phosphates. It is found in grains of the si/,, of a pin-head ; 

 color yellow to yellowish-red; transparent; hardness about 5. 

 An analysis of - 85 gram of the mineral mixed with matrix 

 (0-585 insoluble in HC1) gave : 



P 9 0» FeO MnO CaO MgO 



It contains some fluorine, which, however, was not determined. 

 The calculated formula is (Fe, Mn, Mg, Ca) 4 P 9 0, + CaF„ hut. the 

 analysis is too imperfect to determine the composition with cer- 

 tainty. The author suggests that perhaps the true formula is 

 I* iy>.-MiF 2 , and then the mineral would he e->entially a triplite 

 containing lime and magnesia. The name given has reference to 



0. T/h f n»H, F/oirer* of CowZ/iw.— Professor Fielder's paper 



on this subject, reviewed in the Slav number of this .Journal, has 

 induced Professor Celakovsky to re-investigate this suhject. mor- 





