eureka!

I found something on a anti-Creationist web site , that's good
because using the op's info should carry more weight with the op's.

Quote:
The density of the dust is given as 3 grams/cubic centimeter.


http://www.infidels.org/library/modern/dave_matson/young-earth/specific_arguments/moon_dust.html

I haven't fully read the article yet , it may be explaining
how a equation is meant to be used.

but I thought it was an amazing find , this is the first time
I have been lucky enough to find it.

I tried a different approach this time after searching the logical
search terms , I just typed into google

1 cm of moon dust weighs

and there was a article.

it looks like there will be a lot more moon dust covering the moon
than .75 inches.

but lets wait till I recalculate it using the now assumed weight
of moon dust and my previous calculation.

3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.