JOURNAL 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. IV APRIL 4, 1914 No. 7 



MINERALOGY. — Supplementary note on the crystal form of 

 hodgkinsonite.^ C. Palache, Harvard University. Com- 

 municated by W. T. Schaller. 



Through the kindness of Mr. McGovern of Frankhn Furnace 

 the writer has been supphed with specimens of a second occurrence 

 of the new mineral hodgkinsonite. These are in the form of veins 

 from 3 to 7 cm. in width consisting of a granular mixture of 

 hodgkinsonite and willemite ; the veins cut the normal f ranklinite 

 ore with well defined boundaries. 



The material of the veins is in large part compact but at quite 

 irregular intervals there occur tiny cavities upon whose waUs are 

 implanted excellent crystals of hodgkinsonite. The crystals do 

 not exceed 2 mm. in length but they are clear and brilliant and 

 give measurements so much better than any obtained on the first- 

 found specimens that the elements have been recalculated and a 

 new table of angles is here presented containing the new data. 

 It will be seen that the forms include the better ones of the first 

 list together with several new ones; the habit is however entirely 

 similar to that first described, the acute pyramids formed by 

 combination of two prisms and two pyramid faces, m and r, 

 having their summits more or less modified by the other planes. 

 The forms previously described as etch forms have not been found 

 on these crystals and they may well be dropped from the form 

 series of the mineral. Nine crystals were measured and gave a 



1 Hodgkinsonite, a New Mineral from Franklin Furnace, N. J. C. Palache and 

 W. T. Schaller, this Journal, 3: 474. 1913. 



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