Translucent cross section of a tourmaline crystal. Tourmaline is a boron-silicate mineral,crystal system trigonal,and commonly forming crystals with an elongate prismatic habitat. It occurs in a number of colors,some of which are much sought after as semi-precious gemstones. This section illustrates the interior structure of the crystal,complete with the tri-axial cross and the six-sided circumference typical for the trigonal crystal symmetry. Actual diameter 80 mm | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Wiersma, Dirk |
Taille de l’image : | 5416 px × 6454 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |