Sand & geology
Reynisfjara
black sandlithic-rich (volcanic/collisional terrane)
What's in the sand
Reynisfjara's pitch-black sand is fragmented basalt from the Katla volcanic system, deposited by the turbulent North Atlantic. The beach is backed by columnar basalt cliffs where rapid cooling of thick lava produced regular hexagonal joints.
References: source 1
Predicted regional composition
Q-F-L (quartz, feldspar, lithic) fractions sampled from the GloPrSM global sand model at this beach's location.
F 11%
L 86%
GloPrSM v1.0.0 (IJ_QFL). GloPrSM is calibrated on modern river sand; beach sand in the same watershed is a reasonable proxy but not identical.
Got a close-up photo of the sand here?
Take a picture with a coin for scale and send it over. We're building a global grain-photo library and this beach isn't in it yet.
Reynisfjara63.4044, -19.0692