It is documented here on the wiki due to being officially-released content by Mojang Studios, even if not present in a final version.
Diamond Chickens act like normal chickens, except when provoked.
As chickens were modified in 2.0 to display neutral behavior, diamond chickens are also neutral. They also explode when aggravated.
|Name||Savegame ID||Numeric ID||Translation key|
Diamond chickens share their ID with chickens, with an additional DiamondChicken boolean to determine if a specified chicken is a diamond chicken.