104 Miner alogical Notices, — Boracite, Lazulite, &c. 



The above results agree with the formula 



(Ca, Fe, Ma) 3 Si + 2 Al Si, 

 and show that the mineral is chemically the same as Epidote. 



RESULTS OF ANALYSIS OF BORACITE FROM LuNEBURG. BY 

 M. C. RAMMELSBERG. 



[From Poggendorff 's Annalen, vol. xlix.] 



Transparent Crystals. Opake Crystals. 



S. G. 2-955 at temp. 12°*5 C. S. G. 2-938 at temp. 11°*5 C. 



According to 

 Arfvedson.* 

 Magnesia .... 30*748 31*124 30-3 



Boracic acid . . 69'252 68*876 69*7 



The quantities of oxygen contained in the magnesia and 

 boracic acid are 12*03 and 47*26 respectively. Hence the 

 composition of boracite is expressed by the formula 



Mg 3 B 4 . 



RESULTS OF ANALYSES OF NOSEAN, HAUYNE, LAZULITE AND 

 ARTIFICIAL ULTRAMARINE, PERFORMED BY M. F. VARREN- 

 TRAPP IN THE LABORATORY OF PROF. HEINRICH ROSE. 



[From Poggendorff's Annalen, vol. xlix.] 



Nosean from the Lake of Laach. 



Oxygen. 



Alumina 32'566 15*20 



Soda 17*837 4*56 



Lime 1-115 0*31 



Silica 35*993 18*70 



Sulphuric acid ... 9*170 5*49 



Iron 0*041 



Chlorine 0'653 



Water 1*847 99*222 



Hauyne from Nieder-Mendig, 



Oxygen. 



Soda 9*118 2-33 



Lime 12*552 3*52 



Alumina 27'415 12-80 



Silica 35-012 18'28 



Sulphuric acid . . . 12-602 7'23 



Sulphur 0-239 



Iron 0-172 



Chlorine 0-581 



Water . 0'619 98*340 



[* The details of Arfvedson's analysis will be found in Phil. Mag. First 

 Series, vol. lxii. p. 358. — Edit.] 



