Cloud is a bright white material mainly used for the construction of clouds.  Like the red and green glowing grid blocks, cloud glows.  Cloud is slightly bouncy (bouncier than a basic material, less bouncy than a Mushroom block), yet is easier to die on than other blocks; while dying on a normal block requires for a 13 block fall, dying on a cloud block only requires an 8.5 block fall.  While cloud costs 150 Gold on the Main and Brazil servers, it only costs 150 Silver on the Friends server.

A Cloud block