## 4 Results
### Metallic Mineralization in Light of the Microscopic and EPMA Studies
Figure 9: _Cont._  
Figure 11: _Cont._  
Figure 10: Ternary diagrams of the chemical composition of Al-spinels in the Fe\({}_{3}\)O\({}_{4}\)-Al\({}_{2}\)O\({}_{3}\)-Cr\({}_{2}\)O\({}_{3}\) (**A**) and Fe\({}_{3}\)O\({}_{4}\)-MgO-Al\({}_{2}\)O\({}_{3}\) (**B**) from the Krzemianka and Udryn Fe-Ti-V deposits in NE Poland. Figure 9: Variation in the content of elements in the chemical composition of magnetite (**A**), ilmenite (**B**), and Al-spinels (**C**) from the Krzemianka and Udryn Fe-Ti-V deposits in NE Poland. Figure 11: BSE images of characteristic sulphide mineralization hosted by magnetite-ilmenite ones from the Krzemianka and Udryn Fe-Ti-V deposits. (**A**) a typical sulphide aggregate in magnetite (mgt)-ilmenite (ilm) ore, in which the primary pyrrhotite (po) and pentlandite (pn) were subject to secondary mineralization processes. They were replaced by sulphide associations with chalcopyrite (cp), siegenite (sie), bravoite (brv), and pyrite with smythite (smy) and by thiospinels (spl). (**B**) pyrrhotite (po) grain subject to pyritization (py) within the magnetite (mgt)-ilmenite (ilm) aggregate; galena (gn) insert is present at the border of pyrite and pyrrhotite, cp—chalcopyrite; (**C**) siegenite (sie) replacement of pyrrhotite (cp) along the cracks. Greenockite and galena (gn) grains associated with low-temperature minerals of the chlorite group (chl); py—pyrite; mgt—magnetic; gck—greenockite; (**D**) sulphide aggregate consisting of pyrrhotite (po), chalcopyrite (cp), siegenite (sie), pentlandite (pn), and Co-bearing pyrite (Co-py), BSEI false colors; (**E**) sphalerite (sp), surrounded by chlorites (chl) in the ilmenite-magnetite ore; (**F**) native bismuth (Bi) inclusion in magnetite (mgt); the aggregate consists of pyrrhotite (po), chalcopyrite (cp), pentlandite (pn), and siegenite (sie), BSEI false colors; (**G**) greenockite (gck) vein in chalcopyrite (cp) and pyrrhotite (po) aggregate hosted by magnetite (mg). Greenockite can be a secondary product of the supergene alteration of Cd-rich sphalerite; (**H**) hessite (hes) inclusion in chalcopyrite (cp) and pyrrhotite (po) aggregate hosted by magnetite-ilmenite ore, BSE. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Mineral** & **Value** & **Fe** & **S** & **Ni** & **Co** & **Cu** & **Zn** \\ \hline  & & **wt\%** & **wt\%** & **wt\%** & **wt\%** & **wt\%** & **wt\%** \\ \hline pyrrhotite & arithmetic mean & 59.53 & 39.06 & 0.61 & 0.16 & 0.04 & 0.03 \\ _(FeS)_ & standard deviation & 0.56 & 0.34 & 0.54 & 0.05 & 0.03 & 0.04 \\  & geometric mean & 59.53 & 39.06 & 0.48 & 0.15 & 0.51 (\(n=46\)) & 0.38 (\(n=42\)) \\  & median & 59.56 & 39.03 & 0.55 & 0.15 & 0.04 & 0.03 \\ (\(n=61\)) & minimum content & 56.13 & 38.34 & 0.19 & 0.05 & b.d.l. & b.d.l. \\  & maximum content & 60.53 & 39.75 & 4.00 & 0.28 & 0.14 & 0.16 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The basic statistical parameters of the chemical composition of pyrrhotite, chalcopyrite, cubanite, talnakhite, and pyrite from the Krzemianka and Udryn Fe-Ti-V deposits. Igeneous pyrrhotite is a hexagonal polymorph that changes along the grain edges into a monoclinic polymorph, which is usually highlighted during the oxidation of polished sections. Monoclinic pyrrhotite was most often replaced by secondary pyrite (Figures 7G and 11A,B). Pyrrite was formed in late processes as a monoclinic pyrrhotite replacement. The characteristic bird's-eye textures, as a result of oxidative conditions during increasing sulphur fugacity \(f\)S\({}_{2}\), were observed (Figure 7G). The chemical composition of pyrite was, on average, 44.1 wt% Fe and 53.0 wt% S and a constant substitution of Co and Ni (Tables 3 and A9). Another product of pyrrhotite transformations was smithite, which was probably formed as a product of the low-temperature decomposition of strongly magnetic monoclinic pyrrhotite (Figure 11A) [41].