## 4 Results  
### Petrographic Features  
Petrographic study for all tested rock samples took place under a polarizing microscope in order to find their primary and secondary assemblage, as well as to find which textural features may influence their physicochemical and physicochemical appearance. These factors may determine their suitability as concrete aggregates. The ultramafic rocks derived from the first ophiolite complex (Veria-Naousa) are serpentinized Iberzolite, harzburgite with a high degree of serpentinization and olivine bearing-orthopyroxite. The harzburgite and Iberzolite are mainly characterized by cat-aclastic texture. Their primary mineralogical assemblage has been mostly obliteratedby alteration and contains few relics of orthopyroxene, clinopyroxene, spinel (Al-spinel and Cr-spinel) and olivine. Serpentine is the main alteration product of harzburgite and presents mesh, bastitic as well as intersertal textures (Figure 3). Furthermore, harzburgite is presented as very serpentinized with relics of orthopyroxene, less clinopyroxene, olivine, as well as magnesiochromite and Cr-spinel. In lesser amounts, chlorite and magnetite also occur. Orthopyroxene presents subhedral porphyroclasts with exsolution lamellae of clinopyroxene in most of them. Plastic deformation is occurred as intense fragments in spinel as well as intragranular microcracks are observed. The ol-orthopyroxene presents generally porphyroclastic texture. It consists of porphyoclast orthopyroxene, rare clinopyroxene, olivine and spinel. Orthopyroxenes exhibit local kink bands, undulatory extinction and frequent exsolution lamellae of clinopyroxene. Serpentine is the dominant alteration product forming mesh texture. Lesser amounts of chlorite and talc and magnetite occur too. The collected ultramafic rocks from the second ophiolite complex (Gerania) are Iberzolite, harzburgite and dunite characterized by variety in the degree of serpentinization (Figure 4). The textures of Iberzolite are protogranular, porphy  
Figure 3: Photomicrographs of: (**a**) spinels in a mass of serpentine in a serpentinized Iberzolite (sample, SV5, XPL); (**b**) relics of clinopyroxene and mesh texture of serpentine presented in a serpentinized Iberzolite (sample SV4, XPL); (**c**) bastitic texture of serpentine in a serpentinized harzburgite (sample SV6, XPL); (**d**) relics of clinopyroxene and mesh texture of serpentine presented in a serpentinized harzburgite (sample SV7, XPL). Abbreviations: opx: orthopyroxene, cpx: clinopyroxene, spr: serpentine, sp: spinel. alastic, olivine, orthopyroxene and clinopyroxene. In small amounts opaque minerals (mainly spinel) are presented. Moreover, strained olivine and orthopyroxene porphyrolcasts occurred, with undulate extinction, strain lamellae and kink banding both in orthopyroxene and clinopyroxene. Serpentine is the main alteration product with mesh and occasionally ribbon textures. Another result of the serpentinization is the replacement of orthopyroxene from bastite, when some orthopyroxene and clinopyroxene crystals are additionally replaced by chlorite and actinolite. Furthermore, in lherzolite, numerous and extended microcracks occurred. Mainly porphyrolastic and partially cataclastic texture is displayed in harzburge. Its primary minerals are olivine, orthopyroxene (exsolution lamellae of clinopyroxene) and less clinopyroxene. Porphychcasts of olivine appeared with intense deformation (strain lamellae, kink banding and undulate extinction) and small-sized unstrained neoblasts. Olivine neoblasts had replaced orthopyroxene crystals. Less chromite and in some cases with rims altered to secondary spinel-type minerals were also observed. Numerous and extended microcracks are also presented in harzburge. The most common mineral is serpentine that displays ribbon texture. Furthermore, chlorite appeared in lesser amounts. The dunite presents cataclastic and locally granular textures, whereas the serpentinized samples show mainly mesh as well as local ribbon and interwoven textures.