The density and porosity of meteorites from the Vatican collection

We have developed a nondestructive technique to measure the densities and p orosities of large (50 g to several kilogram) meteorite samples and have be gun a systematic measurement program starting with meteorites from the Vati can Observatory collection. Our technique utilizes a modified Archimedean m ethod (40 mu m glass spheres substituting for the fluid) to determine bulk density, and an unusually large He pycnometer to determine grain density. F rom these, the porosity is calculated. We report here our first results for 89 samples (nearly doubling the published database on porosities of meteor ite hand samples), including porosities of 35 different meteorites. These i nclude several types not previously reported: eight iron meteorites, six st ony-iron meteorites, an enstatite chondrite, the CI carbonaceous chondrite Orgueil, and the shergottite-nakhlatite-chassignite (SNC) meteorite Nakhla.