| P number: | P528029 |
|---|---|
| Caption: | Photomicrograph of limestone, Sandend Group. Light: XPL. Magnification: x2.5. Glenisla Quarry, Keith, Banffshire, Scotland. |
| Description: | Grey foliated crystalline limestone of medium grain size. This specimen is Dalradian Supergroup (Precambrian) in age. BGS sample number SL 238. British Geological Survey Petrology Collection sample number S 35271. Photomicrograph details: Light: XPL, Magnification: x2.5. The twinned interlocking calcite grains of which the rock is composed are elongated in the plane of foliation and reach 4 mm in length. Quartz is present as a subordinate mineral and forms grains, often with crystal faces, usually about 0.3 mm but up to 0.5 mm across. The content of quartz is about 5-7 per cent, but is variable. Opaque black and yellow granular matter is also present in the rock and is certainly in part pyrite, but perhaps includes graphite. Muscovite and phlogopite are present as accessory minerals, and rare alkali feldspar also occurs. |
| Date taken: | Sun Jun 25 00:00:00 GMT 1905 |
| Photographer: | Unknown |
| Copyright statement: | Unknown |
| Orientation: | Landscape |
| Size: | 341.99 KB; 1000 x 663 pixels; 85 x 56 mm (print at 300 DPI); 265 x 175 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Unsorted Images |
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