Collage of nine types of sand
Sand is a granular material composed of finely divided rock and mineral particles. This collage depicts samples of nine types of sand, in rows from left to right:
  1. Glass sand from Kauai, Hawaii
  2. Dune sand from the Gobi Desert
  3. Quartz sand with green glauconite from Estonia
  4. Volcanic sand with reddish weathered basalt from Maui, Hawaii
  5. Biogenic coral sand from Molokai, Hawaii
  6. Coral pink sand from Utah
  7. Volcanic glass sand from California
  8. Garnet sand from Emerald Creek, Idaho
  9. Olivine sand from Papakolea, HawaiiPhotograph credit: Siim Sepp