Table 1.

Sampling sites and their basic characteristics.

Site characterization					Micro-CT scans characterization
Site name		GPS	Characterization	Lithology	Dimensions (mm)	Weathered state	Void space (~porosity)
Siculiana Marina (SM)	1S	37.3388700 N, 13.3967000 E	Sites 1S and 1A are located near road to Siculiana Marina. Samples were collected from gypsum at western side of the outcrop.	Flat “honey-color” selenitic crystals (~5–10 cm in length) in aggregates	20 × 10 × 5	Almost uncorroded with secondary crust	0.8% (uncorroded part) 17.5% (crust)
	1A			White crystalline crystals (~ 10 cm in length) in aggregates	20 × 15 × 8	Almost uncorroded with secondary crust	1.2% (uncorroded part) 15.1% (crust)
Santa Elisabetta (SE)	2	37.4472489 N, 13.5474772 E	Gypsum outcrops at western side of Santa Elisabetta Mountain	Flat “honey-color” selenitic crystals (~15–20 cm in length) in aggregates	25 × 13 × 4	Uncorroded	1.8%
Monte Perrera (MP)	3	37.3807706 N, 13.4527739 E	Gypsum outcrops at south-east side of Monte Perrera	White hard course-grain aggregate gypsum crust with fine-grained matrix underneath, with presence of cracks	10 × 10 × 5	Partially corroded with secondary crust	14.8% (corroded part) 23.4% (crust)
					15 × 10 × 10	Deeply corroded with secondary crust	16.4%
Monte Gibliscemi (MG)	4	37.2094297 N, 14.2623708 E	Blocks of gypsum located at western side of Monte Gibliscemi	Coarse-grain aggregate	23 × 10 × 10	Uncorroded	8.1%