Taken for the Flick Macro Mondays challenge "Bubbles".
We live close to Nailsea in North Somerset, where there used to be a thriving glass-making industry. The waste glass from the furnaces is called "cullet". Since it contains impurities and trapped gases, it was usually dumped and sometimes found its way into a sort of hardcore for garden paths etc. The piece is about 1" thick and the small section shown here is illuminated from behind by an LED torch. As it has spent some years in the garden, you can see small bits of moss/lichen in some of the crevices. The visible extent of the image is about 1.25".
