I've had a couple of similar run-ins on o-bey - and they also refused to back down. Wouldn't even consider how ridiculous their policy was regarding the items I was trying to sell. One was a piece from a country that had been embargoed in the past - the item wasn't on the embargo list and wasn't illegal to sell, as I'd had owned it since long before the temporary embargo. The other was a piece of California fossil whale bone - not a CITES item at all and not a part of any modern whale species. Seemed to go in one ear and out the other, and they just said if I attempted to relist it, my account would be pulled and I would be permanently banned from o-bey. As in your case, there were plenty of others selling the exact same things; big sellers seem to get free rein on their site.
They and their managers obviously have zero knowledge apart from their computer scripts. The minerals which make Trent so pretty are bound up in silica, and it isn't poisonous - even if one could manage to swallow a cobble or slab, it'd just pass through. I thought etsy was a CRAFT site? Do they not know that oil, acrylic and other paints contain things like cadmium, chromium, and other "toxic" substances? Do they not know what is in ink? What about that vanadium in those Zambian emeralds? Or the copper in all those copper and sterling findings? I can see a policy which requires warning labels for liability purposes, but banning stuff just because toxic materials are part of its makeup is ridiculous and hypocritical: in that case, etsy shouldn't be selling much of anything.