Re: Steve Duggan's photo
How about some more information? How hard is it, are the different colors of different hardnesses, does it fizz in acid, what kind of rock was it found with, where did it come from?
Two ideas come to mind: first, the pattern is very similar to that of fossil feeding traces (mud-eating marine worms, etc.). Second, the fine straight lines across the dark curves look somewhat like features seen in porcelain jaspers. Are these lines just color differences or are they cracks?
A very interesting specimen.
From MikeR - March 26, 2010 at 21:37:56