This is a Yin Yang Sun Moon Crystal Grid made out of Maple wood. These are made to order, you can choose between approximately 4, 6, 8, 10, 12 and 14" in diameter and 4mm thick. This is just for the grid, stones much be purchased separately.
Generally speaking, yin is characterized as feminine, still, dark, negative, and an inward energy. On the other hand, yang is characterized as masculine, energetic, hot, bright, positive, and an outward energy.
Yin and yang elements come in pairs, such as the moon and the sun, female and male, dark and bright, cold and hot, passive and active, and so on.
But it is important to note that yin and yang are not static or mutually exclusive terms.