I have one pendulum. She is obsidian and really beautiful, like a deep dark sparkling pool. I saw her in a shop a few years ago and couldn't leave the shop until I had purchased her.
We were meant to work together. I borrowed a friends rose quartz pendulum once which I found quite zingy, so would like to add a few more to my collection of crystals.
If I'm not carrying my pendulum then my necklace makes a good one.