167 



TAB. LXXXIL 



The figures here represented approach the dodecaedron 

 as nearly as any that I have yet met with of British origin. 

 It will be readily seen that the edges of the four-sided 

 pyramid, as truncated on the left- hand JIgure, if continued 

 so as to obliterate the octaedral faces, would form, with the 

 help of the four-sided column, eight of the faces of the 

 dodecaedron, the other four faces being hid in the gangue 5 

 and, if with a short column, the faces would be all rhom- 

 boidal ; but if the column be long, the columnar faces will 

 be hexagonal. As yet we have not seen a dodecaedron 

 with both pyramids complete. These specimens are not 

 so black as most, and are modified very roughly. They 

 have also somewhat of a rusty ochraceous hue, probably 

 holding more oxidated iron than usual. 



We are obliged for this specimen to our friend Mr. 

 Richard Phillips. We have some like it, but much 

 smaller. 



