Water Power Engineers Monday, 22 August 2011 Lens at 40mm, ISO 100, ƒ/7.1, 1/400s Snapped Aug 22, 2011 at 4:39pm South DakotaSioux FallsFalls ParkWaterfallHydroelectric 1 comment left 8.22.11 Comments Alexander Micek Monday, August 22, 2011 — 10:55pm I think this is polished quartzite, though I can’t be sure.
Alexander Micek Monday, August 22, 2011 — 10:55pm I think this is polished quartzite, though I can’t be sure.
Comments
Alexander Micek
I think this is polished quartzite, though I can’t be sure.