This is another fee-pay mine which let's you search through their buckets of dirt for gemstones like rubies, sapphires, garnets, topaz, emeralds, and colored quartz varieties.  This probably isn't a great place for rockhound purists who want to dig their own dirt, but should be a fun place for kids.  Find out more at their website:

http://www.rokgem.com/gemine/index.html