I'm doing business with Indonesia now selling miniature landscapes made of volcanic glass and rendered and polished by a genius. The volcanic glass could be from a number of Timor eruptions including Krakatoa. They are as were when they first cooled hundreds of years ago. Some look like a photograph of trees, sky, clouds and meadows. I just mat and frame them for America. The polisher calls them moss jasper.

Here is one I call The Red Wave. (they are small) https://www.etsy.com/listing/1119305727/scenic-java-moss-agate-emerald-cut-gifts?click_key=ade4fdbdc99d88607d44dcbc5956922478284