Fig. 8From: Weathering assessment approach for building sandstone using hyperspectral imaging techniqueMicroscopic characteristics of the weathering process of building sandstone: a unweathered; b slightly weathered with exfoliation of mineral particles; c slightly weathered with the expansion of pores; d moderately weathered with mineral hydrolysis; e moderately weathered with biological colonization; f highly weathered with biological weathered crustBack to article page