| P number: | P521528 |
|---|---|
| Caption: | Mineral specimen of prehnite. Castle Hill, 3.2 km west-south-west of Kilbirnie, Ayrshire. |
| Description: | The specimen shows the mineral prehnite forming a globular or botryoidal crust. It has an orange colour which may be caused by the presence of a secondary coating of iron oxide on its surface. British Geological Survey Petrology Collection sample number E 3317A. The mineral prehnite is silicate of calcium and aluminium. This specimen is from a vesicle or cavity in a Dalmeny-type basalt plug or volcanic neck, probably of Carboniferous age. The specimen was presented by John Smith, the author of the book 'Semi-precious stones of Carrick' (1910). Prehnite is commonly found as green or greenish-white reniform, stalactititc or mammillary aggregates. It has a hardness of 6-6.5 on Moh's scale of hardness and a perfect basal cleavage. It is translucent with a vitreous lustre. |
| Date taken: | Wed Jan 01 00:00:00 GMT 2003 |
| Photographer: | Unknown |
| Copyright statement: | NERC |
| Orientation: | Landscape |
| Size: | 170.58 KB; 1000 x 723 pixels; 85 x 61 mm (print at 300 DPI); 265 x 191 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Best of BGS Images/ Rocks and minerals |
Loading...
Loading...
Reviews
There is currently no feedback