These are easy little pendants that are super quick, easy, and make great gifts to anybody! I've found solid colors to turn out best and dark colors don't show the shattered inside. Shattered marbles also make awesome rings!
Bake marbles in the oven for 20 minutes at 400〫F.
(I found changing the temperature has little affect.)
I baked the marbles in foil on a cookie sheet.
Immediately after removing the marbles from the oven, put them in ice water (be careful, the marbles are extremely hot). This will cause the marbles to crack! Also be careful of some weak marbles that may break entirely.
Put the metal bead and bead cap on the earring hook (you may also use the small looped jewelry wire things.. I wasn't sure what they were called). Bend the hook to somewhat hold the bead cap on the bottom and cut the excess wire.
Next you can either use jewelry glue to attach the marble to the little top you have just made, or use hot glue. I tried both, and the hot glue tends to fall off occasionally.
Now just add a cute chain and you're finished!