This is steel shot. It’s a tumbling media used by jewellers to harden and smooth the surfaces of softer metals, such as silver and gold.
The various sized and shaped pellets of steel are put into a canister with a small amount of water, a drop of soap, and a small or textured piece of jewellery. The contraption then spins around for about an hour, and what comes out now has a nice shiny finish.
To avoid rusting they need to be rinsed and then air dried after each use.
The bright towel Lauren laid them on caught my eye, so I figured I’d get a picture of that up close.
I took this with a 90mm macro lens, shooting at 1/200 and f25, with an ISO of 100. I had a strobe with a Magbounce floating up and to the left.