bulk density, page-3

That's soils, we're talking about rocks.

Cotboy. yes that's correct. Their models run on volume and convert to mass via a SG (specific gravity). If the conversion is out then the mass would be out. Any geo worth his salt would test SG directly. The only problem is voidage, which can only be tested via core samples. It's the voidage that makes the soil's SG lower than the mineral's SG, and the prevalence of organic matter.