“New insights into the fine-grained, opaque selenide veinlets of the Sierra de Cacheuta, Mendoza Province, Argentina. Photo 1, please compare Photo 10, and Photo 22. Dispersed-light dark field image of Se-vein Type-4 (2.2-cm-thick, 6.6-cm-wide, embedded in resin, surface rolling grinded, with 1.200 mesh SiC abrasive), with layers and lenses of klockmannite (dark grey) and clausthalite (light grey) forming a strongly foliated and folded mélange (cf. Section 3.2.1). The spotty and lens-like aggregates of the trachytic host-rock fragments (h-r) are partly rotated; the vein selvage, host-rock fragments (h-r) and diagonal fractures are stained by various alteration products, such as goethite (dark brown), azurite and chalcomenite (blue), and malachite (green). Günter Grundmann photo, Frank N. Keutsch collection. For further explanations see reference: „The Sierra de Cacheuta Vein-Type Se Mineralization, Mendoza Province, Argentina.“ By Günter Grundmann and Hans-Jürgen Förster. In: Minerals 2018, 8, 127; doi:10.3390/min8040127. ”