Surely you're aware that this has devolved into a semantical discussion. I've never seen much point in such things but I can play along.
> Gravel weighs less that the rock it is made from?
It's very difficult to weigh stone until you remove it from the earth since getting a scale under it is difficult. Even more difficult is defining the stone until it is actually separated. However we can get a good approximation of the weight of a region of stone by sampling it to determine the density and then just multiplying that by the volume once the region is defined. After it's blasted out of the earth then finding all the pieces is impossible and they get mixed up with all the others. Many will drift off on the breeze or filter down through cracks in the earth. Huge amounts of energy are released over a very brief time to liberate these chunks and debris from the earth. But the total amount of energy required to blast the stone free is miniscule compared to the amount of energy that then has to be applied over a longer period tolift this stone to 150'.
It's this lifting to 150' part that people don't seem to get. Carrying it up a bit at a time as you might on ramps is grossly inefficient since you also must lift your own body weight to get the stone up. Anyone with experience will understand this simple concept viscerally. You can get a gut ache trying to carry and drag stuff all day that you might not even notice since your soar back will take precedence.
Of course it's quite logical that pulverized stone weighs a lot less than solid stone on many levels. A truck load of loose stone has lots of air between the pieces. Much stone has been reduced to dust. Even the bouyancy in air is greater per unit weight for pulverized stone in some cases. If you are making ten trips per day lifting basketfuls or truckloads out then at the end of the day those who hauled the pulverized stone lifted much less weight. If you use two trucks with the same amount of fuel the truck that lifted the pulverized stone will lift much less weight. If you can only lift 1000 lbs at a time those lifting 500 lbs of debris will accomplish far more work than those who can't lift the 1000 lb stones. This is a major consideration if you're trying to lift lots of stone with women and young children.
You may think all these considerations are trivial but in actuality they are all immensely semantical and should never be out of sight. The nature of reality and language and their interplay is exceedingly complex. If we don't cut to the chase we can easily miss those things that are important. It's easy to talk right past one another with "nonsense" and "semantics".
I shouldn't do this but after hundreds of semantical answers to an argument it can be hard to resist.