Even if there is water on the moon,
the samples could not have contained any.

They where taken from the very surface.

The ground was heated up a lot (it was day on Moon during the
whole mission).
And water quickly evaporates in vacuum.

So there is no chance that surface rocks contain water.
The surface must be very dry anyhow.

If there is water, its below the surface, where it can not
exit quickly.

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I would also not expect any minerals formed under water,
as this needs liquid water.
But the moon is either too cold or to hot for liquid water.
I guess its more comet remains (durty ice) lying sub-surface.