Brown drupe.
The item id for Coconut Half in unturned is 1453. You can use this ID with the commands below to spawn the item, give it to a player or buy it on a modded economy server.
Useable: Consumeable
Size_X: 1
Size_Y: 1
Size_Z: 0.225
Food: 7
Water: 3
ConsumeAudioClip: Sounds/EatSquishy.mp3