Question
Hi, Can you tell what this is why it appears so odd?
Answer
Hello Harness,
This specimen looks very much like silica froth that accompanies the eruption of silica-rich magma. For example, obsidian. The obsidian dome in Long Valley, California, is coated with this type of material.
Compositionally, it is comparable to rhyolite - a volcanic rock, but textually, it is a volcanic glass (pumice) that forms as gas - mostly H2O and CO2 escape from the depressurized magma.
Cool stuff. Where did you say you found it?
Mike
