Coin

A coin is a collectible item in Super Mario 64. They are found in every level. When collected, if the player has taken damage, they will recover 1 bar of health. They can be found around the map, in boxes, and found from enemies. All 15 main courses has a coin counter. If the player gets a total of 100 coins, a star will appear. There is a 100 coin star in every main course.

Red Coin
A red coin is a special variant of a coin that appears in several levels and all 15 main courses. When collected, they recover 2 health and increase the coin counter by 2. If 8 are collected, a star will appear. There is an unused behavior for a red coin to stay at a fixed distance in front of the player, baiting the player to chase it.

Blue Coin
A blue coin is a special variant of a coin that appears in some levels. When collected, they recover 5 health and increase the coin counter by 5. They are bigger than regular coins and red coins. They can be found by killing certain enemies and pressing blue coin switches, switches which spawn several blue coins for a specific amount of time. When the timer ends, the blue coins will disappear. The timer automatically ends if all blue coins from a blue coin switch are collected.

White Coin
White coins are the texture for coins, and the color is altered for whichever coin is spawned. However, some people have reported that white coins can appear in some levels. There is not a consistent effect of collecting the white coin.

Purple Coin
Purple coins are anomalous versions of coins that have been reported to appear in certain levels of Super Mario 64. They are usually hidden, and can unlock things. There is no consistent thing it unlocks, but one report claims that they suddenly gained temporary tetrachromacy, the condition where the afflicted person can see more colors than the average person. How this happened is unknown.

Coin Shadow
Found in the files of Super Mario 64 is an icon of a transparent coin. It is believed this would have been used when the player had no coins, or all the coins in the level are collected.