| P number: | P000185 |
|---|---|
| Old photograph number: | MNS00296 |
| Caption: | Processing of Scottish mica. Pitlochry Depot (January 1945). Perthshire. Plates of mica illustrating the various commercial grades. |
| Description: | Processing of Scottish mica. Pitlochry Depot (January 1945). Perthshire. Plates of mica illustrating the various commercial grades. The photograph shows eight grades of mica. One to four are grades of staining. Five to seven are grades of spotting. Eight is a mica showing zoning, a structural imperfection. Note the re-entrant angles on three and four where imperfections have been cut out. Mica is graded for commercial purposes according to type, colour and freedom from staining. The primary division is into Muscovite or White Mica and Phlogopite or Amber Mica. Muscovite is subdivided into two types 'Ruby' and 'Green' types. Both are colourless when less than 0.5 mm. but when greater than this size they have reddish and greenish tinges respectively. |
| Date taken: | Tue Jan 01 00:00:00 GMT 1946 |
| Photographer: | Unknown |
| Copyright statement: | Unknown |
| Acknowledgment: | This image was digitized with grant-in-aid from SCRAN the Scottish Cultural Resources Access Network |
| Orientation: | Landscape |
| Size: | 174.51 KB; 1000 x 632 pixels; 85 x 54 mm (print at 300 DPI); 265 x 167 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Unsorted Images |
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