Pebble of andesite,an extrusive volcanic (igneous) rock with a typical porphyritic texture,being that of twinned crystals of feldspar (white) floating in an amorphous matrix of solid lava,here of brick-red colour. This porphyritic texture is caused by exsolution,a process of separation that takes place during successive phases of crystallisation and solidification in the lava. Pebble's actual width is 100 mm | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Wiersma, Dirk |
Taille de l’image : | 5616 px × 3744 px |
Model Release : | Non requis |
Property Release : | Non requis |
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