Anne Helmenstine
It's actually pretty hard to find a sandy beach on the Big Island. This sand is from a park on Keauhou Bay. It's mainly white, with a bit of pink from coral. The sand is soft and powdery. Shell-based sand feels different from rock-based sand.
In Hawaii, it's obvious beaches aren't all composed of the same material. The next time you're at a beach, take a close look at the grains of the sand, to see what they are made of.