There are some wonderful estate and antique pieces on this site, and I love this scarab pin. Made of delicate plique a jour enamel, which is like stained glass and translucent when held up to the light, it’s always wonderful to see one of these old pieces that has survived intact. Available for USD $750 and made of silver; site says it is set with an opal but does not indicate if it’s synthetic, glass, or a doublet/triplet. I can’t link directly to it as the site uses Flash, but find it here under pendants/pins.