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[Eddie P]

Hi everyone.  Am hoping one of you knows where this conglomerate stone/pudding stone/brecciated marble is from.   I've tested it and it fizzes happily in vinegar, so despite being called 'bamboo jasper' by Chinese sellers it most certainly isn't jasper but a calcite-based rock (calcite matrix, calcite clasts).   Sometimes the matrix is a bit redder than this photo.  No one out there in China seems to know anything about it.  Seen attributions to Mexico and Brazil but they are from metaphysical folk who think it's a silicate and don't seem well informed.

[lithicbeads]

It is not puddingstone. It is a flat pebble conglomerate which has recently been marketed from Asia. I have collected and cut it from Montana and Wyoming and have posted pendants here made from  the rough I collected. there are a bunch of scientific papers  published on how it forms. It can vary in color quite a bit.There is a stone from Mississippi that is quite similar with the exception that the matrix is specular hematite and ilmenite while  flat pebble conglomerate has limestone pebbles and a fine grained limestone mash as matrix. It is a nearshore ocean formation created by extreme storm activity in the form of waves.

[Eddie P]

Thank you for your thoughts Frank - I found your earlier posts and your lovely work with the flat pebble conglomerate.  Your geological conclusions seem sound. Interestingly, I think this stuff was briefly available in quite large chunks (of middling quality) in the 70s/80s.  I just picked up a couple of tables with flat pebble stone tops, 20 inches diameter, 1 inch thick.  They came out of a very old lady's house where everything was last decorated in the 1970s/80s here in Britain.  They are probably Chinese manufacture. I was very pleased because they were a fraction of the price of boring white marble tops.

[AgateLicker]

Yeah, yeah! All hail turbidites and shallow sea deposition habits! Most likely a dolostone if it fizzed and like Frank says, rip up clasts got knocked about on the sea shore in a tidal flat or marginal area (marsh, etc.) and then out washed and settled in deeper water as Bouma A.