Amethyst crystals. Amethyst is a purple variety of quartz or silica oxide (SiO2) that is itself usually white or clear. The colouring of amethyst is caused by compounds of iron or manganese. It occurs most usually as crystals formed inside voids or cracks in volcanic rocks. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Bond, Martin |
Bildgröße: | 5616 px × 3744 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |