85 



TAB. CXLV. 



CUPRUM oxygenizatum. 

 Crystallized Red Oxide of Copper. 



Div. 1. Crystallized. 



I have already figured some Cubical and Octaedral Ruby 

 Coppers. The present one from Cornwall is extremely 

 rare and curious, as it has a remarkable modification — the 

 cubo-octaedron of Haiiy, with the addition of an obtuse 

 four-sided pyramid on each cubic face, formed as it were of 

 somewhat distinct plates. In one crystal this pyramid is 

 formed into a cross, the plates of which it is composed being 

 notched or incomplete in the centre of their edges, and 

 complete at the corners : see the right hand upper figure. 

 With these are crystals of similar forms, of very pure Copper, 

 composed of oblong particles with a reticulated appearance, 

 as if they were some of the others, of an anterior formation, 

 having been deprived of their oxygen. These crystals are 

 very extraordinary, as they comprehend the Octaedron 

 with truncated edges : they have also truncated and bevelled 

 solid angles, making a very compound crystal : see the 

 left hand figure. The intermediate varieties are the dode- 

 caedron and octaedron, truncated at the solid angles. The 



VOL. II. i 



