I visited the Crater of Diamonds State Park near Murfreesboro, Arkansas several times in 1985, 1987, and again in 2012. I consider it a sort of religious pilgrimage for rockhounds. Tell me, where else in the world can a member of the general public sit down on a world class diamond pipe (lamproite rock intrusion in this case), and for a few bucks a day, dig away to their heart's content looking for diamonds. You aren't likely to find a "Star of Arkansas," but if you are diligent, you can find a diamond. I found the small stone pictured above. Check out this link to the park if you want to know more about this site. There was a battle going on for several years between a group of mining companies and park preservationists. The mining companies (Apparently too lazy to go to Africa, Australia, Canada or some other corner of the world and find another diamond pipe) wanted to turn the place into a big hole in the ground! Well, they finally got the state of Arkansas to pass a law that would have allowed commercial mining of the park. After testing a 10,000 ton bulk sample of the lamproite, they recovered 207 diamnonds; weighing a total of 45.75 carats. The mining companies decided that wasn't enough to justify a commercial operation. Rockhounds rejoice! Visit the park and find your own diamond.
Sorry folks, the above diamond isn't for sale. It's the only one I've found!