Texture of the dated rocks, outcrop pattern (A, B) and scanned thin sections (C to F). — A, Clefcy quarry dark vaugnerite with pink, light syenite vein and veinlet. Hammer-pick for scale. — B, Habeaurupt vaugnerite with transitional contact between a leucocratic type (left) and a mesocratic type (right), with a darker enclave (arrows). Hammer-head for scale. — C, granite-gneiss, relatively fine-grained, its foliation marked by sub-parallel, elongated and sinuous biotite sections (arrows). — D, Clefcy melanocratic vaugnerite (top: Bt∼40% Amp∼30%) and a biotite-free vein of pink syenite-granite, its color due to hematite dust in albite phenocrysts (arrow). — E, Barançon vaugnerite, characterized by its oversized biotite crystals (arrows) even in this mesocratic type, with green amphibole ± chlorite. — F, Habeaurupt vaugnerite, biotite-dominated, melanocratic type.