This is the Damous Executus, the Iris of Truth. It's imprinted on the Gateway to the Nether, they say if you see it spinning that you can open the door to chaos. This separates chaos and order.
Clockwise to center we have:
Bright Green: Nature
Deep Green: Wind
Blue: Water
Purple: Metal
Red: Fire
Brown: Earth
White/Black: Light and Shadow
From these seven all others are born...

Can you see it spinning?