• Serpentine

In all samples of clinopyroxenites, serpentine actively replaces olivine through the net of microcracks (Figure 8a,b). Among two types of serpentinites are distinguished according to morphology and chemical composition: A (coarse-lamellar, supposedly antigorite) and B (fibrous, apparently lizardite). Serpentine A is developed in clinopyroxenites I and II. Serpentine B is present in clinopyroxenite III. Serpentine A replaces the most ferruginous olivine (22.4–27.9 wt.% FeO) (Table 3, No 1–4) and, in turn, contains the highest iron content (4.6–12.8 wt.% FeO) (Table 7, No 1–5). Serpentine B is less ferruginous (1.1–2.2 wt.% FeO) (Table 7, No 6–10) than serpentine A and replaces olivine with a lower iron content (12.3– 13.8 wt.% FeO) (Table 3, No 5–7) X(Fa) = 0.13–0.15 (Table 3, No 6–10). Coarse grains of porous secondary magnetite, tremolite and chalcopyrite are deposited in olivine together with serpentine A (Figure 8b). Serpentine A also corrodes primary magnetite grains and forms symplectic intergrowths with secondary magnetite (Figure 8a). In clinopyroxenite II, serpentine A is developed at the contacts of olivine and clinopyroxene grains. Here, together with tremolite, it is present in the marginal parts of sulfide segregations of bornitechalcopyrite paragenesis (Figure 8c). In clinopyroxenite III, lamellar (fibrous) aggregates of serpentine B replace pyrite and chalcopyrite grains (Figure 8d).

**Figure 8.** Serpentinite in samples of clinopyroxenites I (**a**,**b**), II (**c**), and III (**d**). (**a**) Relationships of serpentine A (Spr A) with primary (Mag 1) and secondary magnetite (Mag 2) in large olivine grain (Ol); (**b**) microcracks in olivine (Ol) filled with serpentine A (Spr A), tremolite (Tr), chalcopyrite (Ccp), and secondary magnetite (Mag 2); (**c**) localization of serpentine A (Spr A) and sulfides of bornite–chalcopyrite paragenesis (Bn-Ccp) in interstices of olivine (Ol) and clinopyroxene (Cpx) grains. Serpentine A (Spr A) together with tremolite (Tr) corrodes the marginal part of sulfide segregation; (**d**) fibrous aggregates of serpentine B (Srp B) corroding the marginal parts of large segregation of pyrite (Py).


**Table 7.** Chemical composition of serpentine in clinopyroxenites I–III (in wt.%).
