Fig. 2
From: Photographic evidence of luminescence during faulting in granite
Comparison of luminescence with two different granites, Fujioka (a and b, run F4-2) and Inada (c and d, run I3-1). Note that Fujioka granite is coarser grained granite. (a) and (c): Images of the specimen before the loading. Size of specimens are 5 cm in diameter and 12 cm in height. (b) and (d): Images of luminescence during their brittle fracture, taken from the same position as the (a) and (c), respectively. Images are not intensified. Bright red and blue-violet spots are identified on the lower half of the specimen for Fujioka granite, while weak blue-violet spots are identified on the lower half of the specimen for Inada granite.