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."
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:
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.