These 8mm round opals feature a polished surface on both sides and edges, with a thickness of approximately 1mm. Their flat, round form offers ample surface area for the vibrant play-of-color to shine. Its transparent base with watery iridescence: Each opal boasts a clear transparent base that showcases vivid flashes of green and blue fire. This transparency allows the opal to virtually disappear within clear glass, highlighting the watery play-of-color for a captivating effect.