Typically fungi metabolize or filter contaminates unless they are heavy metals in which case they may absorb them into the fruiting body. Probably doesn’t matter either way in psilocybin mushrooms as people would only be eating a gram or so anyway, and not very often. It would be a much bigger deal in edibles where people eat much larger amounts much more often. I believe the black is carbon and the red chips have iron oxide.

I have seen wood-loving mushrooms (including allenii and cyanescens as you’ve shown here) growing in these black landscaping chips around the Bay. I have wondered what these commercial wood chips are made of. Seems like sometimes they are made from chipped industrial wood, for example treated decking material or plywood which can contain creosote and CCA (chromated copper arsenate). The dark black color which is so trendy these days is applied with a dye, and the dye especially likes to penetrate bone-dry commercial castoff wood. To what extent do you think the chemical weirdness in the commercial wood chips makes it into the fruiting bodies?