The material for this study was obtained thru the courtesy of Mr. James G. Manchester, who collected a number of specimens of dolomitic limestone from the above locality which yielded on solution highly modified pyrite crystals of somewhat unique development. The crystals, which show a considerable variation in size, are in every instance distorted by a flattening parallel to one cube direction which in several cases results in the suppressing of the modifying planes adjacent to these two cube faces; this is brought out in the frontispiece, in which figure 1 represents a photograph of one of the specimens, and figure 2 a drawing of one of the crystals measured. Another characteristic which distinguishes these crystals is the presence of prominences on planes of the pyritohedron (210) and the octahedron. One rare trapezohedron (766) and several rare diploids were observed, one of the latter constituting a new form for pyrite. All five diploids appear in the upper right hand forward octant of the crystal figured, the new one being next above s. The distribution of the formson the ten crystals measured is given below:

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not have access to this content, please speak to your institutional administrator if you feel you should have access.