Table 1 Iron and Manganese percentage of black-blue stains on granite and CIELab color coordinates
From: Green chitosan: thiourea dioxide cleaning gel for manganese stains on granite and glass substrates
Churches | Granite | Elemental Analysis | CIELab coordinates | |||||
|---|---|---|---|---|---|---|---|---|
Fe (%) | Fest/Feun | Mn (%) | Mnst/Mnun | L* | a* | b* | ||
Sta. Marinha | Un | 1.01 ± 0.19 | 0.96 | 0.08 ± 0.02 | 18.73 | |||
St | 0.97 ± 0.11 | 1.50 ± 0.77 | 23.86 ± 1.03 | 3.36 ± 0.34 | 3.90 ± 1.20 | |||
St. Tiago | Un | 0.72 ± 0.21 | 0.85 | 0.08 ± 0.04 | 17.25 | |||
St | 0.61 ± 0.30 | 1.38 ± 0.53 | 21.16 ± 1.39 | 3.48 ± 0.47 | 3.07 ± 0.37 | |||
N.S. Guadalupe | Un | 0.79 ± 0.31 | 1.31 | 0.05 ± 0.03 | 23.35 | |||
St | 1.04 ± 0.20 | 1.17 ± 0.11 | 24.04 ± 2.40 | 3.59 ± 0.74 | 4.15 ± 1.98 | |||