This is a Mandala crystal grid made out of Birch wood. A mandala is a spiritual and ritual symbol in Hinduism and Buddhism, representing the universe. In common use, "mandala" has become a generic term for any diagram, chart or geometric pattern that represents the cosmos metaphysically or symbolically; a microcosm of the universe.
Crystal grid and healing sets are groups of stones that go together for a purpose. Sets of crystals and stones are used for ritual magickal or spiritual crystal healing purposes or with Reiki-Seichim energy work for healing. Some are generalized and others have specific purposes.
These are 6 inches in diameter and 1/4" thick. This is just for the grid, stones much be purchased separately.