By: magic-gigapans
Image: Robin Rohrback, Mid-Atlantic Geo-Image Collection
License: Creative Commons Non Commercial ⧉

Uploaded: 13 May 2020
Last Updated: 1 Jun 2020

118 megapixels
11,888 x 9,928 pixels
39.6 in X 33.1 in at 300dpi
2,975 pixels per inch

Reticulite, also known by the poetic name "thread lace scoria", is the "none more pumice" of glassy volcanic rocks. Like pumice, it is a volcanic glass. Unlike pumice, the gas bubbles in reticulite have all burst, leaving behind only the delicate interstitial mesh. Reticulite forms in particularly vigorous lava fountains which reach at least 300 meters into the air. Pressure at that altitude is low enough that it causes the gases dissolved within the lava to rapidly exsolve. This sample was graciously donated by Margie Kalua, and is 1 inch long.