Detail of contact between original quartz grain and recrystallized quartz-mica fibers. The contact is sharp and appears as a 'reaction front' generated by the fluid phase that presumably reacted with the original quartz. The fibers consist of interlayered recrystallized quartz and mica flakes. The original quartz grain displays fractures subparallel to the quartz-mica fibers; some fractures appear stylolitic, and some are coated with fluid inclusions. The fractures are probably important in enhancing the recrystallization process. (Sample WR 041, White Range, central Australia) (0.65 mm)