Work out rock density instantly with clear inputs, formula shown and shareable results.
Density is mass over volume, and since water is 1 g/cm3 the numerical value is also the specific gravity. 685 g in 250 cm3 gives 2.74 g/cm3, typical of granite or limestone. Rock densities cluster tightly by type - 2.2-2.5 for sedimentary, 2.6-2.8 for granitic and 2.9-3.1 for basaltic - so density alone narrows identification considerably.
Density
rho = mass / volume
Specific gravity
SG = rock density / water density (1 g/cm3)
By water displacement, sealing porous samples with wax first so pore space is not flooded.
Because gravity surveys detect density contrasts, which is how ore bodies, salt domes and buried basins are mapped.