Photomicrographs and SEM-CL images showing the textural characteristics of muscovite and quartz related to the QTS and MOSS of the mineralized veins of Panasqueira. (a) Vertical section perpendicular to the horizontal vein planes showing a muscovite-rich selvage associated with early apatite and overlain by wolframite. (b) and (c) transmitted light images of hydrothermal quartz respectively formed during to the QTS and the MOSS. These sections were cut horizontally and perpendicular to the axis of quartz. (d) and (e) SEM-CL images displaying textural characteristics of quartz formed during the QTS and the MOSS. These hydrothermal quartz exhibit thin, contrasted, oscillatory growth zoning. The dense network of CL-dark structures corresponds to fractures healed by non-luminescent quartz. Quartz can be partially corroded (red dashed line in e) and marked by sector zoning. Ap: Apatite, Cst: Cassiterite, Ms: Muscovite, Qz: Quartz, Tur: Tourmaline, Wlf: Wolframite.