pristine white sand dune contrasting blue sky

aeolian air alabaster alamogordo albedo alkaline arid basic beige blue calcium cerulean cloudless contrasting contrasts crescent crystals delineated desert deserted desertification desolate dihydrate dry dune dunes erosion geologic geology grass grows gypsum high highly leeward longitudinal mexico mineral mineralogy minerals monument national natural new pile pristine reflective saltation sand sands sharply side sky slide stark still sulfate surface tuft unvegetated white