Earlier quoted context omitted.
Indeed! Then there is all kinds of specialty sands - say, when replacing the sand in our local athletics union long jump pits, I learned that one should use sand from river beds (as opposed to sand crushed at a plant) as the river sand is much less likely to cause abrasions, seeing as all the sharp edges have been worn away as the sand has been shifted back and forth by the river current... Sand is not just sand.
The best night's sleep I ever had was on the sand of a turn in a dry creek bed, after a very long day's hike. It must have had a big rock underneath that caught the day's warmth and kept me toasty all night. And the sand itself felt like floating on a cloud. It was a magical place. And one of the stupidest I ever slept in due to the risk of flash floods.
Glad you made it out safe, with a story to boot.