8 



although perhaps not before noticed, may commonly be 

 found in thin layers, or separate in the small partings in the 

 Newcastle coals, from nearly pellucid to nearly opaque 

 white, not unfrequently prismatically coloured, or coated with 

 silvery or golden coloured pyrites, and may sometimes be 

 found very beautiful. Wishing to make the subject familiar, 

 I felt a pleasure in introducing a thing so easily procured, 



