Accurate Density Determination of Various Natural Stones Employing Archimedes’ Principle and a New Non-Destructive Liquid Pycnometer for Solids

In this study we explore various non-destructive methods for the determination of density of 27 non-porous natural stones. Among the methods investigated the most accurate method was found to be the mass-based suspension method that uses Archimedes principle, with costs of equipment less than 20$. We have used this density measurement method to measure densities of natural stones and copper reference cube in the range of 1.07 – 8.93 g×cm-3, for stones that have volumes less than 16.4 cm3. The measurement are in excellent agreement with more precise methods that use a 4 decimal place analytical balance. The measurement uncertainty of the method was assessed with a Cu density reference cube and was found to be of the order of 0.1% in measuring the volume of stones with arbitrary shape. Finally, we provide details of the design features of a new liquid-based pycnometer that can measure the density of irregular shape natural stones without the need to form a powder. This pycnometer can also be used to measure density changes in liquids as a function of temperature and solute concentration.