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On measuring volumes of small pieces

I read a news report that gave the dimensions of the Governador
Valaderes recently auctioned as being .08 inches by .08 inches by .16
inches.  This is a volume of only around .0168 cubic centimeters (2.54
cm = 1 inch), which gives a density of .28 g divided by .0168 cm or 16.7
g/cc.  I believe the dimensions given are not accurate or not maximum
dimensions and somewhat larger values should have been used. A modest
increase, say .1 by .1 by .2 inches, is not quite enough since then the
volume is only about twice as much as the previous estimate yet still
gives a density exceeding 8 g/cc.  Stone meteorites are typically less
than 3.5 g/cc.  While I don't know SNC density I am certain it is
nowhere near 8 g/cc, and assume it is under 3.5 g/cc. 

Mass is fairly easy to measure for anyone with a good scale, but volume
is another matter.  I would guess that for micromounts measuring the
volume of what may be an irregular shaped and small piece is simply not
easy unless great care is taken.  My hypothesis in lieu of a description
by someone who was present is that the reported set of dimensions may
have been based on using a ruler or tape graduated by sixteenths of an
inch. It could have been easy with a quick measure of a nonsymmetric
shape to err by a linear factor approaching two in any dimension when
using the smallest subticks on the measuring stick.  This would then
give the correct neighborhood for the density, given the .28 g mass.
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