Musannaf Ibn Abi Shayba 18:125

Abu Bakr narrated to us, he said: Muhammad ibn Bakr narrated to us, from Ibn Jurayj, from Ibn Abi Najih, from Mujahid, that he said regarding the tip of the nose (rawtha): "One-third of the blood money (diya)." "If it reaches the nasal bone (marin), then the full blood money is due. If the tip of the nose (arnaba) or other than it is injured, as long as it does not reach the bone, then it is calculated according to the proportion of the tip of the nose."