672 Ford and Bradley — Footeite and Connellite. 



proved to be a decomposable copper silicate, presumably a form 

 of chrysocolla. 



Optical and crystallographic characters. — The color of the 

 mineral is a fine deep azure-bine. When examined under the 

 microscope the slender crystals showed no dichroism and 

 always gave an extinction parallel to the prismatic edges. 

 From faces in the prism zone only indistinct interference figures 

 could be obtained, but sections cut perpendicular to that zone 

 gave very distinct normal uniaxial figures. The mineral is 

 optically positive. By immersion in high refracting liquids 

 the refractive indices were determined as : co = 1*730, e = 

 1-754, e-co = -024. 



The crystallization is hexagonal. It was possible to mount 

 several crystals under the microscope so that the prism angles 

 might be measured. These gave angles close to the required 

 60°. One crystal was measured on the reflecting goniometer 

 and, although the minute character of the faces together 

 with their vertical striations made accurate measurements 

 impossible, the average of a series of the prism angles obtained 

 was 60° 44/. These measurements show clearly that the min- 

 eral must be hexagonal and not tetragonal. Only a few 

 instances were observed where terminal faces could be distin- 

 guished. They were so small, however, and so distorted and 

 irregular in their development, that it was impossible to deter- 

 mine their character. 



Blowpipe reactions, etc. — The mineral has a fusibility of 2*0, 

 being readily fusible in the bunsen burner flame, giving at the 

 same time a bluish green flame color. It gives the flame 

 color when heated in the candle flame but does not fuse. In 

 the closed tube it yields water which reacts strongly acid. It 

 is insoluble in water but readily dissolves in acids and gives 

 the customary reactions for chlorine, sulphuric acid and copper 

 in the solutions. It is also readily soluble in ammonium 

 hydroxide. 



Connellite from the Tintic district. — Through the courtesy 

 of Mr. Lazard Calm and of Mr. George L. English of the 

 Ward's Natural Science Establishment in Rochester, the 

 authors have been enabled to examine quite a series of speci- 

 mens from this district. They come from the Grand Central 

 mine, Eureka, Utah. The character of the mineral and its 

 occurrence is strikingly similar to that of the connellite from 

 Bisbee. In fact, if the specimens from the two localities had 

 not been authentically labeled, they would most probably have 

 been ascribed to the same district. 



The connellite from the Tintic district occurs usually as 

 small masses with a columnar structure. The prisms do not 

 often become separate and detached from each other as is the 



