(6.35mm = 1/4 inch). The item "Handcrafted Australian Lightning Ridge Black Opal Bead Necklace (685a)" is in sale since Sunday, July 12, 2020. This item is in the category "Jewelry & Watches\Handcrafted & Artisan Jewelry\Necklaces & Pendants". The seller is "opalwholesalers" and is located in Kensington Gardens, SA. This item can be shipped worldwide.