Visualization of porosity in vltavín

You may know that the only European tektites – glassy rocks formed by the impact of a space body – are vltavains.

After the collision with the 1km-sized asteroid, the underlying rock melted and was ejected into the upper atmosphere, where it quickly solidified in the form of amorphous glass.

Blown glass often contains a lot of air bubbles - pores.

Such an object can serve well for example porosity analysis. With our CT system DeskTOM (RX Solutions), we scanned one sample of vltavine out of curiosity.

We evaluated and visualized the present porosity with the voxel data analysis program VGSTUDIO MAX (Volume Graphics). After applying the filter, we got an interesting result.

It can be seen from the samples that the pores generally have an elongated (prolate) shape and a significantly homogeneous (uniform) orientation.

This would correspond to the basic ideas about the formation of vltavine – the shape and orientation of the pores show the deformation that the melt went through during solidification while passing through the atmosphere.

Although some vltavas still retain their drop shape today, for most of them the final shape is determined by impact fragmentation and chemical and mechanical corrosion during the next 15 million years of the stone's fate.

Variability in the degree of pore elongation (and the study of internal structure in general) can help identify areas of preferential deformation of materials and reconstruct the original orientation and shape.