Issue 42

M. Davydova et alii, Frattura ed Integrità Strutturale, 42 (2017) 170-180; DOI: 10.3221/IGF-ESIS.42.18 174 Figure 4: a) 3D X-ray Computed Tomography of the fragment (sizes ~28mm ×9mm×9mm and mass 2.26g); b) photo of the fragment; c) 2D Computed Tomography of the upper part of the fragment. Figure 5 : Petrography-analysis. A plagioclase grain is indicated by a red line, a potassium feldspar - by a blue line, a quartz - by a green line, and a amphiboles - by a yellow line (cross-polarized light, magnification × 50). The grain size analysis gives us the mean grain size. It was measured ten field of vision with total number of grain being 167. Most plagioclase grains have the size of about 0.25-0.5 mm; potassium feldspar – 0.5-1.0 mm; quartz and amphiboles a) b) crack crack c)