20 



A BLUE MINERAL FROM NEW MEXICO— PACKARD. vol.xvii. 



The material obtained for analysis as above described is dull, 

 earthy, and of a blue color, resembling vivianite in these respects, 

 but is in the form of a powder. Its grains act feebly on j)olarized light, 

 but present no crystalline forms. It does not lose its color in hot acids 

 although it is partly decomposed, yielding magnesia. Before the blow- 

 pipe it does not color the cold borax bead, becomes white on ignition 

 but does not fuse, and then gives a pink color with cobalt solution. 

 After treatment with HCl it gives no reaction for manganese on fusing 

 witli soda. It contains no phosphoric acid or sulphur. 



The analyses of different samples varied somewhat for the reasons 

 Avhich have been given above. Three which accord well are as follows: 



Ignition 

 SiOj ..- 

 MgO-... 

 FeO - - - . 

 AljO,... 

 Na,0 . . . 

 KiO . . . . 



These analyses show a chemical resemblance to talc, although the 

 physical proi)erties of the twominerals arc different. Oneof the analyses 

 (No. XLYII) given iuHiutze's Handbuch, under talc, is almost identical 

 with the above. It runs as follows: SiO^ 63.95, FeO O.GO, MgO 28.25, 

 H2O 6.65, with 0.78 AI2O3. 



The carbonate accompanying the mineral is rich in magnesia which, 

 with the abundant silica and iron oxide, would supply the materials 

 for its composition. 



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