Geo 730: March 14, Day 438: Spherulites

A nice example of spherulites, devitrification structures formed when glass crystallizes into minerals like feldspar and quartz. I have the sense that they form quite quickly after an eruption. Vapor phase minerals must, by their nature, form while the lava is still quite hot, and I've seen cases where those minerals coat spherulites- meaning the spherulites formed first.

Note: If you decide to visit this spot, please see Tuesday's comments on safety issues.

Photo unmodified. August 19, 2011. FlashEarth Location.