Density of Limestone

I suppose that I should be weighing all of the stones that I carry but, being an engineer, I'll be using a tape measure and calculator instead. Most of the stone that I'm carrying is limestone, and since I live at the base of the Niagara Escarpment, it is that type of limestone.

The density of limestone apparently varies from 2.1 to 2.7 g/cc. The density of water is 1 g/cc or 62.4 lbs per cubic foot.  Since its easier to think in cubic feet than cc's for something as large as this, we'll go with limestone weighing somewhere between 130 and 170 lbs per cubic foot. The middle of that range is 150 and a nice round number to remember. So, I declare that the average density of the stone that I am using is 150 lbs per cubic foot. I found one mention of the density of Niagara Escarpment Dolomite Limestone at 165 lbs per cubic foot, so I think my value is fair.

The structure that I am assembling has the stones packed fairly closely together, but I'm guessing that there is probably around 10% air space between the stones. The footprint of the structure is 6 feet by 3 feet and the height right now varies between 4 and 12 inches with an average around 7. Therefore, the current total weight of the stone that I've carried to work so far is about 6 x 3 x 7 / 12 x 0.9 x 150 = 1,420 lbs.  The weights that I post from now on will be based on this type of calculation.

September 18, 2012 (1,420 lbs)