I think that's actually the result! I read @glofish's proposal as suggesting that bacterial excretions(?) indiscriminately dissolve the rock. The paper (linke

I think that's actually the result! I read @glofish's proposal as suggesting that bacterial excretions(?) indiscriminately dissolve the rock. The paper (linked above) does try to address this in a few ways. Iron, the putative energy source, is specifically concentrated on the surface of the inoculated samples--but other metals aren't. The bacteria are also mostly found on the mineral edges. They discuss this near Figure 5/6 and in the supplement.