One thing about that, though... the chain might obstruct a little in scrying, so choose a chain that you can move so that it can hang in the clasp while you are using it as a pendulum, and choose a thin chain."Wear a crystal pendulum as a necklace so you’re always ready to do a little scrying."
Pendulum Scrying: How to Use a Pendulum for Divination
Now, this is not a crystal but a specially created divination pendant. The glass vial has been filled with mugwort and yarrow, but it looks like the bottle can be opened and filled with something else, for example, if one wishes to look for gold, one can place a small amount of gold in the vial, aso.
Based on The Witch of Lupine Hollow: 30 Ways to Live a More Magickal Life Everyday