Collection: Opals

Opals are unique, amorphous mineraloids celebrated for their mesmerizing "play-of- color," a optical phenomenon that causes flashes of iridescent rainbow hues to shift and dance as the stone is viewed from different angles. Unlike most crystalline gemstones, opals are composed of billions of submicroscopic silica spheres packed together with a water content that typically ranges from 6% to 10%. They form over millions of years when seasonal rains soak into the earth, dissolving silica from sandstone and carrying the rich solution down into subterranean cracks and cavities. As the water slowly evaporates, it leaves behind these uniform stacks of silica spheres, which act like tiny natural prisms to bend and diffract light into brilliant spectral colors. While the vast majority of mined material is "common opal" (or potch) that lacks this fiery rainbow effect, rare precious varieties—such as the highly valued black opal, ethereal white opal, and fiery Mexican opal—remain deeply coveted for fine jewelry and stand as the traditional birthstone for October.