#hydrothermal veins

• altaite — A rare metallic mineral, a lead telluride with the chemical formula PbTe, crystallizing in the cubic (isometric) system; it stands out structurally due to a yellowish-white or tin-white color with bright yellow reflections, high density, and perfect cleavage. It was initially discovered in the Altai Mountains, from which it derives its name, encountered in hydrothermal veins often associated with native gold and other tellurides.
• Ankerite — A mineral belonging to the carbonate class, consisting of a natural calcium, magnesium, iron, and manganese carbonate, isomorphic with dolomite. It crystallizes in the rhombohedral system, typically presenting a white, gray, yellowish, or brown color (upon weathering) and a vitreous to pearly luster. It is frequently found as a gangue mineral in hydrothermal veins associated with ore deposits.