You are indeed correct my friend.
In the earth moving world what you describe is called "Bucket Swell". That is, when you drive a bucket loader into say a gravel bank, and then back out, because the gravel in the bucket has been loosened and not as compacted as it was in the ground, it swells.
The best way to buy any earthern product is by tonnage, but at least here in Maine, rock, gravel, sand, etc is still sold by the yard, which is an inexact science, but change is hard in that industry.
Road builders get run into "Bucket Swell" a lot when they are making cuts and fills for new roads. When they calculate a cut through a hillside,they must automatically make a 15% increase in the amount of fill moved because of bucket swell. It can make the difference between profit and loss, which was posted in RG LeTourneau's book when he failed to do this and paid dearly when he built the road to the Hoover Dam (Boulder Dam then).
Scottscoaled wrote:You can lead them to water but you can't make them drink.
A solid block of coal. Takes up so much space. crack it in half, and it all ready takes up more space. Take the two halfs of the original block, crack them in half. They too take up more space. All this is if they fit back together perfectly. Once they become misaligned, they take up more space. That drama keeps going. As much as you would think they "pack together", they really have all ready taken up more space, and have more surfaces that are misaligned. Basic physics. One extreme to another. From more to less. This case it's more dense to less dense.