Large Hole Black Tourmalinated Quartz Concave Faceted Rondelles are 16mm diameter in size, have a vitreous luster, show expert concave facets creating brilliance, are symmetrical with a matched quality, present as transparent Quartz bodies with Black Tourmaline needles, the Crystal Quartz beads appear black due to their heavy needle consistency, and these large hole beads have an inside diameter of 2.5mm. AAA