*4.2.7 Serpentine*

**Wt% 1 2 3 4 5 6 7** SiO2 47.36 46.75 40.64 41.80 41.84 42.52 41.36 TiO2 0.03 0.00 0.00 0.00 0.06 0.00 0.03 Al2O3 0.48 0.63 0.17 0.35 0.86 0.60 0.38 Cr2O3 0.01 0.00 0.01 0.02 0.01 0.03 0.00 FeO\* 9.88 11.22 10.50 15.14 13.84 13.71 11.09 MnO 0.20 0.10 0.19 0.21 0.25 0.18 0.26 NiO 0.27 0.13 0.23 0.14 0.10 0.19 0.01 ZnO 0.14 0.24 0.58 0.21 0.27 0.00 0.30 MgO 33.21 30.50 36.36 28.77 29.53 29.35 31.96 CaO 0.27 0.42 0.11 0.98 0.32 0.37 0.14 Na2O 0.07 0.05 0.03 0.03 0.04 0.00 0.03 F 0.01 0.09 0.09 0.09 0.05 0.09 0.09 Cl 0.02 0.02 0.02 0.02 0.02 0.01 0.00 Total 92.0 90.2 88.9 87.8 87.2 87.1 85.6

*Mineralogy - Significance and Applications*

Si 4.298 4.354 3.911 4.141 4.132 4.190 4.107 Ti 0.002 0.000 0.000 0.000 0.004 0.000 0.002 Al 0.052 0.069 0.019 0.041 0.100 0.070 0.044 Cr 0.001 0.000 0.001 0.001 0.001 0.002 0.000 Fe 0.750 0.874 0.845 1.255 1.143 1.130 0.921 Mn 0.016 0.008 0.015 0.018 0.021 0.015 0.022 Ni 0.020 0.010 0.018 0.011 0.008 0.015 0.001 Zn 0.009 0.017 0.041 0.015 0.019 0.000 0.022 Mg 4.493 4.234 5.216 4.249 4.347 4.312 4.732 Ca 0.027 0.042 0.011 0.104 0.034 0.039 0.015 Na 0.012 0.009 0.006 0.005 0.007 0.000 0.005 P *9.679 9.616 10.082 9.840 9.817 9.774 9.871*

*Chemical composition (wt%) and atom per formula unit (apfu) of serpentines on the basis of 14 O (CV-67).*

*Chalki basalt serpentines shown as type lizardite and chrysotile (after [16]).*

apfu

**Table 7.**

**Figure 10.**

**38**

Another less abundant secondary mineral after olivine in Chalki basalt is the serpentine. Their chemistry (**Table 7**) and plot (**Figure 10**) reveal clearly that they are mostly of lizardite and chrysotile types.
