Pendulums are simple in that they can only give very few answers and you only ask yes or no questions.
Yes ~ a backwards and forwards direction.
No ~ a side to side direction.
Maybe ~ a diagonal direction, from the lower left to upper right corners of the circle.
Don't Want To Answer ~ a diagonal direction , from the lower right to the upper left corners of the circle.
Probably Yes ~ a clockwise circle.
Probably Not ~ an anti-clockwise circle.
These are usually the responses a pendulum will give (these responses are copied from WMA)
When you get a pendulum you ask it to show you the answers and it's will respond sometimes they aren't always like they are in the above so you do need to ask, especially with your own jewellery.
To use a pendulum you hold it in your power hand with at least 3-4 inches of cord/chain and ask a question, you must hold it steady so you don't interfere with it.
Pendulums work by use of (and people do believe different things)
2. Your higher self.
These are what makes it move.
I hope this was helpful :)