Black Heart Murano Style Glass Bead with Solid 925 Sterling Silver Core for Pandora, Biagi, Chamilia, Troll and More Bracelets general gifts. $5.99. Hole Size: 4.5 mm. Weight: 2.95 grams. Made of .925 Sterling Silver Single Core. Compatible with 3mm and smaller Snake Chain bracelets. Handmade lampwork glass bead. Save 80% Off!