Worry stone

Worry stones are smooth, polished gemstones, usually in the shape of an oval with a thumb-sized indentation, used for relaxation or anxiety relief. Worry stones are typically around 3 centimetres (1 in) in size. They are used by holding the stone between the index finger and thumb and gently moving one's thumb back and forth across the stone. The action of moving one's thumb back and forth across the stone is thought to reduce stress, but there is no conclusive scientific evidence to support this.

Worry stones may also be called palm stones, thumb stones, fidget stones, soothing stones, or sensory stones.