Bertrandite crystals, a selection of specimens of this crystallized mineral species.
Bertrandite is a mineral, and here you’ll find a number of collector’s items presented with a description, one or more photos and sometimes a video.
These bertrandites are for sale.
It is a beryllium sorosilicate with the chemical composition Be₄Si₂O₇(OH)₂ and the orthorhombic crystal system.