• 45  of  63
Uploaded on:
17/03/2009 09:58:09
Type:
Digital Asset
File Size:
150.83 KB
Dimensions:
1000 x 626 pixels
128 views 4 downloads
P number: P528072
Caption: Photograph showing grades of commercial mica.
Description: Photograph showing grades of commercial mica, numbers 1-7 are Indian and number 8 is Brazilian. The illustration is from a publication that dealt with the features of commercial mica in Scotland that was published during the Second World War. Mica was graded on type, colour and freedom from staining. The primary division is into muscovite or white mica and phlogopite or amber mica. Muscovite is further subdivided into ruby, green and spotted types having seven, three and three clarity grades respectively. Mica was further classified by size: extra specials over 48 square inches; specials 36-48 square inches, then grades number 1 to number 7, 24-36 to less than 1 square inches respectively. During the Second World War mica was processed at the main sorting factory at Pitlochry which opened in August 1943. It had a staff of six, for the first few weeks under the direction of Mr. A.B. Mudie of the Eastern Mica Company and later under Mrs. D.G. Readdie (the wife of Mr. D.G. Readdie, of the Ministry of Supply, Mica Control department). The staff complement increased to 36 in November 1943.
Date taken: 25/06/1905
Photographer: Unknown
Copyright statement: Unknown
Orientation: Landscape
Size: 150.83 KB; 1000 x 626 pixels; 85 x 53 mm (print at 300 DPI); 265 x 166 mm (screen at 96 DPI);
Average Rating: Not yet rated
Categories: Unsorted Images  

Reviews

There is currently no feedback