Français : Le verre a une cassure de type conchoïdale English: Glass with a conchoidal fracture I, the copyright holder of this work, hereby publish it...
extracted image: “EX LIBRIS JOHN SINKANKAS” bookplate - Essai sur la turquoise et sur la calaite (IA EssaiSurLaTurquoiseEtSurLaCalaite) (page 2 crop).jpg....
DescriptionConchoidal.JPG cassure conchoidale English: Conchoidal fracture, illustrated by the broken surface on a piece of obsidian (volcanic glass)...
