| P number: | P521530 |
|---|---|
| Caption: | Mineral specimen of agate amygdale. Dunure Railway, Brown Carrick Hills, Ayrshire. |
| Description: | The sample is an agate amygdale, formed of concentrically-banded pinkish-white chalcedony with a centre of crystalline slightly smokey quartz. British Geological Survey Petrology Collection sample number E 3310A. Both chalcedony and quartz are forms of silica (SiO2). Agate amygdale. Amygdales formed of concentrically-banded chacedony with a centre of crystalline quartz; both chalcedony and quartz are forms of silica (SiO2). The amygdale forms by the filling of gas cavities in the lava by silica gels deposited by silica-bearing solutions as the lava cools. The exact nature of formation of agate is still unknown and many theories have been put forward over the last hunded years. The specimen is from the Lower Old Red Sandstone, Maybole Volcanic Series. The specimen was presented by John Smith, the author of the book 'Semi-precious stones of Carrick' (1910). |
| Date taken: | Wed Jan 01 00:00:00 GMT 2003 |
| Photographer: | Unknown |
| Copyright statement: | NERC |
| Orientation: | Landscape |
| Size: | 155.40 KB; 1000 x 775 pixels; 85 x 66 mm (print at 300 DPI); 265 x 205 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Unsorted Images |
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