We capped off a winter ski visit to NC with a trip here in February 2013. The flume is indoors, and we had a great time sifting through the rock buckets. Afterwards a staff member goes through your findings and explains what type of mineral, crystal or gem was found and gives you approximate values. We bought a $30 bucket and found sapphires, rubies and emeralds. They were not necessarily high quality but gems nonetheless! Where they do get you is that to actually get the gems polished or made into jewelry is very expensive...about $100-$200.
That said it was a highlight of my 6 year old daughter's trip to North Carolina. We would go again!