Quartz crystals. These are also known as rock crystals. Quartz (silicon dioxide) is colourless when pure,but the presence of impurities can give a range of colours including white,pink,yellow,blue,green and smoky brown. The colourless variety is highly prized by collectors. Quartz is one of the commonest minerals in the Earth's crust (12% by volume) | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / TH FOTO-WERBUNG |
Bildgröße: | 4504 px × 3121 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |