Obsidian is volcanic glass. It forms when magma (molten rock) is ejected into the air during volcanic activity and chills (cools) so quickly that mineral crystals do not have a chance to form. Obsidian breaks with the conchoidal fracture characteristic of all glass. It is usually black,but may have bands or inclusions that create various optical effects,including a reflective 'sheen' in silver,gold or even rainbow colors | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Arem, Joel |
Bildgröße: | 3851 px × 2550 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: |
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