Torbernite Crystal Cluster — Margabal Mine, Aveyron, France

Torbernite is among the most visually striking uranium phosphate minerals known, and the Margabal Mine in the Aveyron department of southern France is recognized as one of its finest worldwide localities. This cluster presents the mineral's signature emerald to grass-green tabular crystals — square-profiled, vitreous to subadamantine in lustre, and arranged in an overlapping rosette to parallel-growth cluster habit that collectors prize above almost all other secondary uranium mineral forms.

Torbernite belongs to the autunite group and forms as a hydrated copper uranyl phosphate through low-temperature alteration of primary uranium minerals in granite-hosted deposits. The Margabal material is particularly noted for its rich colour saturation and well-developed crystal terminations. As with all torbernite, this specimen is best stored in a sealed container or stable humidity environment to prevent dehydration to metatorbernite — though the transition is reversible, the crystal habit is best preserved with modest care.

A classic of the radioactive mineral canon from a benchmark French locality.

Approx. specimen size: 25mm x 15mm x 10mm

Approx. specimen weight: 5.64 grams

Approx. specimen activity on an SE International Ranger EXP: 60 000 CPM