I thought I had listed rhyolite before but I can't find it.

This is a polished river pebble from Scotland. It came from a river in South Ayrshire. We often find jasper there and it was picked up under the assumption that it was an orange jasper pebble. It wasn't until we polished it that we could make out the kind of bigger crystals floating to the top that indicates both an igneous rock rather than a sedimentary one, and that it might be rhyolite. So here we are.

This stuff comes from volacanic areas. We might be completely wrong and it could just be an orange jasper. Either way, both are pretty cool.