Gold Block

Gold Blocks are golden Brick Blocks that appear in New Super Mario Bros. 2. They appear when Mario or Luigi claims at least 10 coins out of a Coin Block. When this happens, Mario or Luigi can wear the Gold Block over his head, thus producing coins from it if he keeps moving, making it very similar in function to the ? Boxes from Super Mario 3D Land. If Mario or Luigi runs fast enough, the number of coins produced from the block increases. When a Gold Block is worn, the face side of it resembles Mario's/Luigi's face. The Gold Block disappears after 100 coins have been collected from it, or if Mario or Luigi is hit while wearing it. While playing in co-op mode, if a player ground-pounds on another player wearing a Gold Block, they will lose the Gold Block as well. If Mario/Luigi grabs the Goal Pole while still wearing the Gold Block, he can continue to get coins from going down the pole and jumping off it, finally losing it after landing on the ground. Hitting one from either side, from above, or while wearing another Gold Block causes 50 coins to spout out of the top before it disappears. The Gold Block will also protect against the stone spell used by the Koopalings in World 6 and World Star, though only once.

Flying Gold Blocks also appear in the game and are seen flying around in their idle golden forms, since there are no flying Coin Blocks. They occasionally appear for every 200,000 points earned and fly above Mario or Luigi on the world map, and can be used right away upon him entering a level, similar to the red Flying ? Blocks in the first New Super Mario Bros. Also, when the score reaches the maximum of 999,999,999 points, Flying Gold Blocks will always appear no matter how many points Mario or Luigi earns.

A trophy of Mario wearing a Gold Block appears in Super Smash Bros. for Nintendo 3DS.

In Super Mario Party, Hidden Blocks resemble Gold Blocks.

New Super Mario Bros. 2

 * Electronic manual description: "While wearing this, Mario will earn coins just by running and jumping!"
 * Note: The block will disappear after producing a certain number of coins, or if you are hit by an enemy."
 * North American website bio: "Hit a repeating coin block enough times and it turns gold, getting stuck on Mario's head. Run as fast as possible with this block attached and watch the coins add up at super speed."
 * European website bio: "Hit some blocks repeatedly and they'll turn into Gold Blocks, which you can either a) wear on your head to leave a trail of coins in your wake, or b) Ground Pound to release a fountain of coins!"

Trivia

 * In the Super Mario Mash-up in Minecraft, Blocks of Gold are replaced by Gold Blocks. 3D pixel art of a Gold Block appears in the world premade for the pack, nearby a normal Brick Block.