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 by Thomas Thomson in 1810 after the scottish mineralogist Thomas Allan. This is a mieral close to epidote and there are 3 types of allanite based on their concentration in cerium, lanthanum, yttrium (rare earth element). The lanthanum variety is radioactive.
This is a quartz, more exactly a transluscent chalcedony (itself a variety of cryptocrystalline quartz) which shows concentric bands sometimes containing opale. Comes in many colors, banded, forming concentric bands, more or less circular up to oval. Their formation is so far discuted : or
Described in 1886 by Charles Friedel who named it after the French mineralogist Gilbert Joseph Adam who found this mineral. Its color depends on the metallic ions present : cuproadamite colored by copper is green, manganoadamite colored by manganese is pink-purple such as cobaltoadamite and
