While I was at the Muskallonge Show a couple of weeks ago, a woman drove from the museum to Muskallonge to show me the following agate:
I was so busy that I forgot to take a picture with her and the rock, and I forgot to get her name. However, it is such an unusual specimen that I wanted to include it anyway in this month’s update.
One of the other dealers said he thought it was man-made. I don’t agree. I have seen similar agate-looking rocks which are actually accumulations from paint booths. However, those usually include more brilliant colors and those specimens are opaque – all of the bands. Furthermore, those paint-rocks all have solid bands, not any with miniature geode gaps.
This specimen looked a lot different than anything I’ve ever seen. Some of the bands appear to be clear chalcedony. I didn’t take a picture of the top of the specimen, but there was sedimentary matrix showing on the top.
My guess is that this is a seam agate that formed in sedimentary rock in a marine environment, perhaps in the tidal flats.
The person who showed me the rock said she purchased it at an estate sale down state.
Do any of you have any more ideas about the genesis of this specimen?