The reason they are allowing people to handle the nickel iron is simply that
there must be many of them in existence. It may well be stable but it is
definitely affected by all the salts in human perspiration. The moon rock is
a little more rare hence the no-touch policy.
It is unfortunate that a touchable leaves people with the impression that
it's OK to touch some things because they saw it in a museum. TopTenDave is
absolutely right on! It's always such a fight to get people to understand
that deterioration is invisible in the short term.

Linda Tanaka
Vancouver Museum, Canada

>In article <[log in to unmask]>,
>David Harvey <[log in to unmask]> wrote:
>
>:If you've been handling the specimen with bare hands?  Stop! The chloride
>:salts and acids found in human persperation can etch fingerprints into almost
>:any metal surface.
>
>You conservators would probably cringe if you knew how many tens
>of thousands of people have handled a nickel iron that is on
>display and touchable at the Ontario Science Centre. It does
>seem pretty stable though...
>
>And they don't let anyone touch the moon rock.
>
>                            regards,
>                              tai
>
>/-----------------------------------------------------------------------\
>|     Tai Viinikka       | "I don't think it was a gas bomb at all,"    |
>|     ------------       | Eddie said, gazing out the window.           |
>|  Dwarven Productions   | "I think it was just a big chunk of dry ice. |
>|     [log in to unmask]       | You Europeans are completely paranoid."      |
>\--------------------------------/Bruce Sterling, Deep Eddy/------------/
>