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
Found in 1821 by P.Ström and named “acmite” from the Greek “point, edge” in reference to the typical pointed crystals. But in 1835 Berzelius named it aegirine after Aegir, the Teutonic god of the sea. Richer in sodium than augite, it oxydizes itself, pruducing chlorite,
