This is awful. As someone who studies pyroclastic flows, this is what I dread seeing. My heart goes out to these communities :( #VolcanDeFuego https://t.co/eDe0npTCIs
Aeolian sands from the Rub al Khali (Empty Quarter) of the UAE. Well-sorted, well-rounded quartz grains with a hematite coating (texturally and mineralogically mature. Frosted surfaces, typical of aeolian sands, records abrasion.