Tanzanite Natural Genuine Facet Rondelle Loose Beads 4.5mm (Qty=18) 18 Loose Genuine Tanzanite Rondelle Beads 4.5mm diameter, medium size for Tanzanite about 2" = 18 beads Though larger for Tanzanite tiny holes use fine and very fine cord Tanzanite has different colors in different lights In daylight these are very nice blue, under photo lamps some have violet blue color