When I went looking for rhinestones, I got unreasonably lucky finding some almost the exact same size and shape as those in the necklace. Though of course those in the necklace are glass and have depth to them. While the ones I found are flat backed plastic, and with a slightly different pattern of facets. But still, a seriously good match.
When I first laid the rhinestones out in a pattern to match the necklace, they didn't look right. That's because those in the necklace are outlined by the silvertone settings while mine were bare. So after much experimenting with many different materials and techniques, I finally decided the best way to mimic the silver setting was to surround the rhinestones with a thin line of silver embossing powder.
Once that little detail was added, it was eerie how well the earrings matched the necklace.