Swarovski crystal is used to make beautiful figurines and jewelry. Although it's very uncommon for the crystal figurines to scratch or break (the only thing that can really scratch or break crystal is another crystal or diamond), the crystals can fall out of the jewelry. There is a quick fix to this (see Step 5) if you need it repaired in a hurry. Otherwise, you can fix the crystal yourself.
Lay your jewelry piece down on a flat surface. Soak a lint-free cloth in some water, and use it to wipe down the piece to give it a quick clean.
Apply a tiny dot of jewelry glue to the tip of a toothpick. You do not want too much glue because it may ooze out from behind the crystal.
Use the tip of the toothpick to apply the glue to the inside of the piece where the crystal is missing. Ensure the entire vacant area is coated with glue.
Pick the crystal up with a pair of tweezers (thinner tweezers for small crystals), and carefully insert the crystal into the vacant hole. Use the tweezers to push the crystal into place. Allow several hours for the glue to completely dry.
Take the jewelry piece back to a Swarovski store if you can not fix it yourself. Swarovski sales associates are happy to repair or replace your piece for you should any crystals ever fall out.