Locality: Berrien, Finistère, Brittany, France
Size: 41 mm x 31 mm x 21 mm (1.6 in. x 1.2 in. x 0.8 in.)
Cluster of clear faden quartz crystals from Berrien, France. This specimen has small amounts of dark organic matter particles in the deep spaces between crystals. Some of it can be removed if the collector so wishes, but I have opted to leave it as is. There are some small inclusions as well.
The term “faden quartz” refers to usually tabular quartz crystals that have a white growth “thread” running through the middle. Faden quartz forms within gradually widening fissures in the host rock, where the crystals rupture and heal as the fissure grows wider (see https://www.mindat.org/min-46656.html.)