Pendant With An X

I think this stone might have been worn as a pendant. There is a double hole (as seen in the first three photos) through which a piece of leather could have been threaded. The holes look big enough for this, but they are filled in with dirt now. Like a number of other stones, this one features a prominent "X." 

There are some other markings on it as well. Sometimes, I wonder about these markings and the ghost images which I see in some stones. Are they intended to be realistic or symbolic scenes, some kind of dreamscape or even a map? I feel there is some meaning there, but it's not something I've been able to determine.