One of my favorite stones is agatized fossil coral. The flower images and the colors enchant. Before setting cabochons in metal I set them in tiny Japanese seed beads. It takes more time for sure, but some stones seem to call out for that treatment so I still do it when I feel it's the best way to highlight it.
Agatized fossil coral
Japanese glass seed beads
twisted brass ring with natural patina
anodized aluminum ring
vintage brass chain
copper-tone lobster clasp
Adjustable from 18-21"
Pendant is just over 3" long including the brass ring.