Geoscience Reference
In-Depth Information
345
346
345
Orange clay brick comprising fired clay (dark
brown) with macropores forming a continuous
network of interconnected voids (yellow); PPT, ×35.
346
Same view as
345
in cross-polarized light,
showing fired brick clay (red) and air voids (dark
green); XPT, ×35.
347
348
347
Yellow clay brick comprising a matrix of fired
clay (brown) with almost no sand. Interconnected
macropores appear dark green; XPT, ×35.
348
Black brick comprising fired shale (brown) with
carbonaceous inclusions (black); PPT, ×35.
349
350
349
Salt crystallization scaling of brick masonry
caused by salt crystallization. Cracks are filled with
secondary deposits of gypsum salts (white) while the
brick appears dark brown; PPT, ×150.
350
Same view as
349
in cross-polarized light. The
fired clay matrix of the brick appears red and the
gypsum deposits in the cracks show first-order grey
interference colours; XPT, ×150.
