Complex sentence: The real "moon rocks" (set of 4) given to the people of the Netherlands is in the Boerhaave Museum in Leiden and a former US investigator says it is worth millions of dollars on the black market.
Split into simpler sentences: The real "moon rocks" (set of 4) given to the people of the Netherlands is in the Boerhaave Museum in Leiden. A former US investigator says they are worth millions of dollars on the black market.