Sand & geology
Papakōlea Beach
green sand
What's in the sand
Papakolea is one of only four green-sand beaches on Earth. The color comes from olivine crystals — a silicate of iron and magnesium — eroded out of the nearby Puu Mahana cinder cone. Olivine is denser than the surrounding basaltic ash, so it accumulates here instead of being washed out to sea.
Predicted regional composition
Q-F-L (quartz, feldspar, lithic) fractions sampled from the GloPrSM global sand model at this beach's location.
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.
Papakōlea Beach18.9357, -155.6463