Slice through a small geode, close-up, viewed in transmitted polarised light. A geode forms when silica (SiO2) precipitates from liquid onto the inside surface of an empty pocket in a host rock. The outer layers are variegated forms of chalcedony (amorphous or non-crystalline silica), with the layers becoming more crystalline towards the centre. Here, a core of quartz (the crystalline form of silica) can be seen. The banded arrangement of crystals are a result of changes in pressure, temperature, and mineral content occurring during the formation process. Magnification: x3.8 when printed 10 centimetres wide.
px | px | dpi | = | cm | x | cm | = | MB |
Details
Creative#:
TOP03207822
Source:
達志影像
Authorization Type:
RM
Release Information:
須由TPG 完整授權
Model Release:
N/A
Property Release:
N/A
Right to Privacy:
No
Same folder images: