Each U.S. state got both sets of rocks, and Gutheinz said he and his students have accounted for nearly all the Apollo 17 rocks, though some are in storage and inaccessible. They have only just begun researching Apollo 11 rocks in the states.
In one known legal sale of moon samples, in 1993, moon soil weighing 0.2 grams from an unmanned Russian probe was auctioned at Sotheby's for $442,500.
Gutheinz, the former U.S. investigator, says ignorance about the rocks is an invitation to thieves, and he should know.
In 1998, he was working for the NASA Office of the Inspector General in a sting operation to uncover fake rocks when he was offered the real Apollo 17 rock — the one given to Honduras — for $5 million.
The rock was recovered and eventually returned to Honduras, but not before a fight in Florida District Court that went down in legal annals as "United States vs. One Lucite Ball Containing Lunar Material (One Moon Rock) and One Ten Inch By Fourteen Inch Wooden Plaque."
The case is not unique.
Malta's Apollo 17 rock was stolen in 2004. In Spain, the newspaper El Mundo this summer reported that the Apollo 17 rock given to the country's former dictator, Francisco Franco, is missing.
Franco died in 1975. The paper quoted his grandson as denying the rock had been sold. He said his mother had lost it, but claimed it was the family's personal possession, to sell if it wished.
Gutheinz says Romania's Apollo 17 rock disappeared after the fall and execution of Nicolae Ceausescu in 1989.
According to Gutheinz and other reports, Pakistan's Apollo 17 rock is missing; so is Nicaragua's, since the Sandinistas came to power in 1979. Afghanistan's Apollo 17 rock sat in Kabul's national museum until it was ransacked in 1996.
In fact, the Netherlands is one of the few countries where the location of both the Apollo 11 and Apollo 17 gift rocks is known. Britain, Australia, Canada and New Zealand are others — though none has rocks from both missions on permanent public display and some have been kept in storage for decades.
The Amsterdam case appears to be not fraud but the result of poor vetting by the Rijksmuseum.
Spokeswoman Xandra van Gelder said the museum checked with NASA after receiving the rock in 1992 from the estate of the late Prime Minister Willem Drees. NASA told the museum, without seeing it, that it was "possible" it was a moon rock.
But it weighed a whopping 89 grams (3.1 ounces). In addition, its gold-colored cardboard plaque does not describe it as a moon rock.
The U.S. ambassador gave Drees the rock during an Oct. 9, 1969 visit by the Apollo 11 astronauts to the Netherlands. Drees's grandson, also named Willem, told the AP his grandfather had been out of office for more than a decade and was nearly deaf and blind in 1969, though his mind was still sharp.
"My guess is that he did not hear well what was said," said the grandson. "He may have formed his own idea about what it was."
The family never thought to question the story before donating the rock, to which it had not attached great importance or monetary value.
AP researcher Randy Herschaft contributed to this story from New York. Reporters Menelaos Hadjicostis in Cyprus, Marianela Jimenez in Costa Rica, Monika Scislowska in Poland, Gonzalo Solano in Ecuador, Andrew Whalen in Peru, Doug Mellgren in Norway, Paul Schemm in Egypt, and Binaj Gurubacharya in Nepal also contributed.