Place marbles in cold dry skillet and set on burner at medium to high heat. Stir marbles constantly as they are being fried. Keep them in pan until they are completely heated through – about 15 to 20 minutes.
Pour marbles into a pan of ice water. The sudden change in temperature will cause the inside of marbles to crackle, while the outside retains its round shape. The crackle inside will pick up rays of light in bright sparkles. If marbles were not completely heated through, they will crackle only a little. Note: You may repeat the process only once to achieve the desired effect or the marbles may break completely.
Cement a bell cap to each marble. Spread prongs of bell cap to conform to curve of marble.
When cement has set, open a jump ring and slip through loop in top of cap. Bend ends of ring back together again.
The marble is now ready to be slipped onto a necklace chain as a pendant or you may place several on a charm type bracelet.