Deb, My Rio catalog shows only base metal clasps (p.10).
Rings & Things has sterling silver magnetic clasps:
Sterling and GF Magnetic Clasps 4.5mm diameter magnet; 6mm outer
diameter of clasp #39-536 Sterling Silver Magnetic Clasp 6.00/ea
#39-636 Gold Fill Magnetic Clasp 7.00/ea 42.60/doz 420.00/GR
Just search for “magnetic” at their website:
http://www.rings-things.com Their toll-free order number in the US and
Canada: 1 (800) 366-2156
Christine in Littleton, Massachusetts, USA, where the morning is
fresh and cool after a terrific rain.