Grains of sand 5; Iceland

More grains of sand, volcanic ash.
These are from the still worm, active volcano Edfell on Heimaey, Iceland.

The grains were photographed on a discecting microscope in the lab and are contrasted with a regular photo of how the sand looks.

Here are the others
Cyprus
Cayman islands
Morar, west coast, Scotland
Tentsmuir, east coast Scotland