Snap Clasp findings from Rings & Things: Also known as "ball and socket" and "button clasps," these are nice clasps for people who have a tough time with lobster clasps and spring rings. You "pop" them open and closed like a snap.
What's the difference between "white" and silver plate? Silver plate has a thin layer of actual silver, so it's a better match for sterling silver jewelry. However, like sterling silver, silver plate can tarnish rapidly. White plate, while slightly grayer, does not discolor easily.