Mineralization at SGX is defined by at least 75 veins within eight major and two minor vein systems. The five largest veins, S19, S8, S2, S7, and S7_1, contain about 33% of SGX’s current mineral resources. Mapping and sampling results showed that ~30% of the vein material is mineralized with massive, semi-massive, veinlet and disseminated galena and sphalerite. Vein widths range from 0.3 m to over 5 m, averaging 0.69 m. Other metallic constituents include small amounts of pyrite, chalcopyrite, hematite, and very small amounts of wire silver, silver-bearing sulfosalts (mainly pyrargyrite), silver-bearing tetrahedrite (freibergite) and possibly acanthite (silver sulphide). The minerals are confined to the veins where they occur as massive accumulations or disseminations. Galena often occurs as massive tabular lenses comprised of coarsely crystalline aggregates or fine-grained granular “steel galena” bodies, which can be up to 1.0 m thick and over 100 m along vertical and horizontal dimensions. Sphalerite, in its dark-coloured, iron-rich variety colloquially known as “blackjack”, occurs with the galena as coarse bands or aggregates. Alternating bands of galena, sphalerite, pyrite, and quartz are common near the vein margins.

At least 21 silver-lead-zinc veins have been identified at the HZG satellite mine, mostly trending NE-SW and bending NNE-SSW toward the western margin. The five largest veins, HZ26, HZ20, HZ22, HZ22E, and HZ15, contain about 59% of HZG’s current mineral resources. Sampling and drilling results indicate that 14% to 23% of the vein material is mineralized, ranging from 0.30 to 1.44 m in width, averaging 0.55 m. Compared to other veins in the district, HZG veins contain distinctly more copper (in chalcopyrite and tetrahedrite) but lower zinc. Tetrahedrite commonly forms massive lenses, likely filling tension gashes that are distributed in relay-like fashion near the vein margins and in ladder-like fashion near the centre of the veins. Chalcopyrite occurs as disseminated crystals in the gangue and in the tetrahedrite. Other sulphides include galena (up to several percent locally) and pyrite.