posted 08-29-2006 01:08 PM
Welcome to collectSPACE, Chris.
If you search the archives, in particular of this forum and "Mercury - Gemini - Apollo", you will find several discussions relating to moon rocks. There are also may be several threads until "News & Events" about related thefts and scams.
Our resources section of collectSPACE has a section dedicated to moon rocks, too.
To answer your specific questions, unless you are referring to naturally-recovered lunar meteorites, a majority of the lunar material now on Earth is illegal for any individual to own. The 872 pounds of moon rocks returned by the Apollo astronauts are a national treasure (less 135 1.142 gram samples that were gifted to other nations).
The Soviet Union returned 0.7 of a pound of lunar material, a tiny fraction of with was legally sold at Sotheby's auction house in 1996 for $400,000. Since then, there hasn't been any known examples of loose moon rock sold publicly.
Lunar dust-stained items have been sold, for amounts ranging from $1000 to $350,000+ over the past 7 years.
There are private and university-run labs that can test samples to determine lunar origin. In addition, if you have what you think is a real rock, you can also contact the NASA Lunar Curator for assistance.