NOTE ON A BLUE MINEKAL, SUPPOSED TO BE ULTRA- 

 MARINE, FROM SILVER CITY, NEW MEXICO. 



By R. L. Packard. 



Some time ago the newspapers* mentioned the discovery of ultra- 

 marine in New Mexico, and Mr. G. I'. Merrill, curator of geology in 

 the U. S. National Museum, who was in Silver City, New Mexico, in 

 the early part of 18!l2, visited the locality wliere the blue mineral 

 referred to is found, and noted its occurrence. He states that the 

 mineral occurs in irregular veins and streaks in the limestone carrying 

 the silver ore (chloride) which is mined at Chloride Flat near Silver 

 City. The specimens he procured for the Museum exhibit the earthy 

 blue substance (which, on casual inspection, does somewhat resemble 

 ultramarine) intimately associated with calcite, chalcedonic ipiartz, 

 and a decomposed ferruginous siliceous nmterial which is iiermeated 

 with calcite, as is also the blue mineral itself; and grains of calcite 

 can be seen mixed with particles of the latter on crushing and examin- 

 ing it with a microscope. 



It was found impossible to free the mineial completely from its asso- 

 ciated gaugue by the Thoulet's solution, and to obtain as pure material 

 as possible for analysis small particles which were free from visible 

 imimrities were carefully picked out, larger ones were crushed and 

 gangue and mineral separated by picking over, the blue fragments 

 being again crushed and picked over. The material so obtained was 

 powdered in an agate mortar, treated with hot dilute hydrochloric 

 acid to dissolve out the calcite and other impurities; the powder was 

 filtered off, washed, and then boiled with a strong solution of carbonate 

 of soda, washed thoroughly, dried at 110°, and ground fine for analysis. 

 With every precaution, however, a few scattered grains of a mineral 

 more strongly refracting than the blue one under investigation were 

 observed under the microscope, showing that perfect separation had not 

 been effected. These grains of foreign matter (quartz) are doubtless 

 the cause of the slight differences in the analyses. 



Iron, London, Jan. 2, 1892: "A New Discovery of Ultramjirine." 

 Proceedings National Mueoum, Vol. XVII — No. 978. 



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