Silverfilled - Beads
Silver filled is similar to gold filled but made with silver. Silver (usually sterling silver) is bonded to the outside of a core of base metal. As far as I know, there is no legal standard for silver filled, although gold filled must be 1/20th 12k gold minimum. Silver filled seems to be used primarily in flatware and serving ware because the bonded coating of silver is much thicker than actual plating with silver.