They don't. They give moon rocks away.
You should probably perform at least the slightest bit of research before you say dumb things.
They never gave away petrified trees. They gave away moon rocks.
We have five real moon rocks, four from Apollo 11 ( 0.05 grams in total) and one from Apollo 17. ( Approximately 1 gram.)
About the piece of petrified wood...
Drees, old prime minister, received it as a private gift on Oct. 9, 1969, from then-U.S. ambassador J. William Middendorf during a visit by the three Apollo 11 astronauts, part of their "Giant Leap" goodwill tour after the first moon landing. It was not given directly by NASA unlike the other five moon rocks.
The museum acquired the rock after the death of former Prime Minister Willem Drees in 1988. Drees had more rocks in his collection, a mistake could easily have been made. The people who gave the rock to the museum ASSUMED it to be a Moon rock.
"Apparently no one thought to doubt it, since it came from the prime minister's collection," Van Gelder said.
Mr Middendorf told how the rock came from the U.S. State Department, but couldn't recall the exact details.