100 N. G. Wells — New Occurrence of Ihjdrogiobeytite. 



hydrogiobertite was found on asbestos by Brugnatelli in tlie 

 Val Bnitta.* Tlie same autlior subsequently examined a simi- 

 lar mineral more tboronglilv and designated it artinite with 

 the formula MgC0,.]\[g(0IlX.3lL0.t The deposit here 

 described seems to agree better with the formula of hydrogio- 

 bertite than with that of any other hydrated basic carbonate 

 of magnesium. The occurrence is remarkable for being a 

 spring deposit. As might l)e expected under these conditions, 

 the specimens aie not very pure and vary consiTlerably from 

 point to point. The deposits are freely exposed to the weather 

 and rain, which may partly account for their irregularity of 

 growth and structure. 



U. S. Geological Survey, June 15, 1910. 



*Z8. Krvst., xxxi, 54, 1899. ' 



tZs. Kryst., xl, 103, 1905, xli, 257, 1906. 



