Moldavite porosity; a 3-D X-ray micro-tomography study

Moldavites are natural glasses formed by distal ejection of meteorite-impact melts; they occur in several shapes (e.g., teardrops, lenticular, dumbbells, spheres) and all contain pores in different sizes. The aim of this study is to describe the distribution of pores in the interior of the scanned objects. The X-ray micro-tomography (mu -XRCT) measurements were utilized to create three-dimensional semi-transparent images of tektites in order to receive information about their porosity. Optimal data interpretation requires the use of proper software programs. For the visualization of the mu -XRCT-data, VG Studio Max 2.0 (Volume Graphics) and ImageJ were utilized. Four tektite samples from the Central European strewn field with different shapes were scanned. The mu -XRCT data depict relations between the distribution of the detected pores and the shape of the tektites. Total volumes, total porosity, number of pores, and pore sizes throughout the tektite samples vary. The evaluated porosity volume of the Bohemian moldavites ranges between 0.024 and 0.085 vol.%. The smallest detected pore has a volume of 0.0003 mm (super 3) , whereas the biggest has a volume of 0.35 mm (super 3) .