Polka Dot Agate found near a little town called Ashwood outside of Madras, Oregon. Is a very interesting agate. It comes in translucent blues, purples and whites. It also has many solid colors such as brown, white, yellow, mustard, tans and of course polkadots, in one or more of the afore mentioned colors. Often there are no polka dots, but these bright colors swirl together to make nice scenes. Sometimes there are also dendrites.