& L. Penfield — SptvngoHte, a new copper mineral, 871 



collection of minerals which be had gathered together within 

 a radius of about two hundred miles, l»ut hi> had n<> idea of 



just where he had found the Specimen, though he thoughl it 

 was from the Globe District. Mr. Spang had forgotten the 

 name i)\' the man from whom he had BOCUred it, BO that until 

 other specimens are found uncertainty must exist about the 

 exact locality and mode of occurrence. On expressing ;i desire 

 to investigate the mineral, Mr. Spang very generously lent me 

 the specimen and has since presented me with it, and it i> now 



deposited in the collection of Professor Geo. J. Brush, at New 



Haven. 



A preliminary blow-pipe examination showed that the min- 

 eral was undoubtedly a new species and essentially a hyd rated 

 Bulphate and chloride of copper, and I take pleasure in not 

 only expressing at this time my thanks to Mr. Spang for his 

 kindness lait also in naming the mineral, which as will be 

 shown, is of unusual interest, SpcmgoUte after him. 



The original specimen, which was about the size of a small 

 hen's egg, consisted of a rounded mass of impure cuprite which 

 was mostly covered with hexagonal crystals of spangolite, aSSO 

 ciated with a few crystals of azurite and some slender pris 

 matic crystals of a copper mineral containing chlorine, probably 

 atacamite. 



The crystallization of spangolite is hexagonal, rhombohedral. 

 The habit of the crystals does not vary much as they all show 

 a prominent hexagonal basal plane and a series of apparently 

 holohedral hexagonal pyramids, which as will be shown must 

 be taken as pyramids of the second order. Some of the crys- 

 tals have the habit of fig. i showing a prism, which is always 



• lull and striated that it gives no reflection of light, ae 

 ciated with pyramids and a basal plane. Others are Hatter, 

 figure 2, and show a large series of pyramids which oscillate 



l. 



2. 



with one another, giving rise to prominent striations which 

 run horizontally about the crystal and make the identification 

 of the pyramids a difficult matter. On the crystals we occa- 

 sionally find a prism of the first order, ///, which i> Bmall but 

 gives good reflections. The material which could be used for 

 the investigation was limited, but great care was taken to 

 select only the best and purest crystals for making the cr 



