Who is Khalid Najmon from Subterranean and what is their importance?

Khalid Najmon is the expedition's geologist. It isn't until the group is deep within the caverns and have already been attacked that Khalid reveals that he is not actually the famous geologist Khalid Najmon, but rather someone who looks a lot like him. He then says that he was sent to keep the diamonds and potential of oil from being discovered. Khalid's real name is never revealed.