4mm Multi Color Umba Sapphire Checkerboard Calibrated Faceted Coin Beads have a vitreous luster, great polish, a calibrated shaped body, the gem bodies are a range of lightly to moderately saturated fancy Sapphire hue with transparent to opaque qualities, and these rare Umba Sapphire beads are a well crafted strand of unique abd stunning quality AAA grade bead group. 1mm drill hole internal diameter