الخميس، 10 مارس 2011

Floating crinoid fossil - fake or real ?


I recently visited a rock shop and saw the beautiful and delicate floating crinoid pictured above.  It wasn't very expensive, and I thought it would look nice in our living room next to the Romanian cave bear tooth.

When I got home, I sat down to type up a label to put in the case, and did a quick internet search for background information.  The Echinoblog has an excellent post on the various forms of pelagic crinoids - ones that attached to floating driftwood, ones that maintained buoyancy with gas-filled floats, stemless floating ones (like the one above), and "dredgers."

Then I encountered a commercial site called Paleodirect, which offered the floating crinoids above; note how their delicate feathery arms are crumbled up, sort of like a jellyfish washed ashore on a beach.  That image contrasts markedly with the one from their site shown inset at the left, which was accompanied by the following notation:
"Over the last number of years, the fossil market had been flooded with numerous fake, painted floating crinoid fossils from the Solnhofen deposits in Bavaria. If you see one for sale that looks like the small photo below, then it is a fake and was painted on the rock, in most cases, not over ANY fossil portion. These are often sold as cheap single pieces or sometimes with 2 or 3 on a small limestone plate. They are sold as "floating crinoid fossils" or Saccocoma. If you Google "SACCOCOMA FOSSILS FOR SALE" you may still find some examples of fakes for sale."
I then looked at my new acquisition with the highest magnification I had available at home; it looks like there may be some actual fossilized material in the center and on some arms, but the bulk of the "feathers" appear to be painted on.  I suppose one could call it an "enchanced" specimen, but I'll be returning it this next week.  The shop is run by highly ethical and knowledgeable members of our local rock/mineral club, so I suspect they acquired the floating crinoid in some bulk lot without much background information.

I know there are experienced rockhounds who read this blog; please feel free to offer your own insights and opinions.

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