Je vous emmène à travers mes vidéos découvrir mon expérience acquise depuis plus de 30 ans a silloner le globe entier à la recherche de pierres précieuses, de rencontre mémorables mais aussi de difficulté parfois …
Named in honor of the German chemist George Ulex (1811-1883). We notice a rare property: if the ends of a thick plate are well polished perpendicular to the longitudinal direction of its crystal fibers, they behave like optical fibers. A Printed text placed below appears
Its name recalls its dominant color : blue in Greek (cyan). Sometimes colorless, but generally blue to bluish green, this gemstone has a hardness ranging, with its texture in plans, from 4.5 (direction of elongation) at 6 to 7 (perpendicular to the elongation). It also
