I believe gemstone mining will be one of the early exports from Luna.

Mrs. Facebook “honey when am I going to get a Lunar diamond like Mrs Bill Gates?”

The best place to hunt gemstones is find where an ancient volcano used to be ( Luna used to be covered with them but have been beaten down flat, like on earth) scrap the top soil and find the old lava tube and mine your way down that tube finding the gemstones that were going to be spewed up.

7 billion potential customers.

I can already see the debeers commercials “if he REALLY loves you he will give you a rock that sparkles that came from the moon”