May 2025 – Epidote

Our mineral of the month for April is epidote. Epidote is a fairly common mineral and occurs in many types of rock. However, it rarely forms stalk-like, rich green shiny crystals like the ones shown here.

Chemical formula: Ca₂(Fe³⁺,Al)Al₂[O|OH|SiO₄|Si₂O₇]

Locality: Escoles Reservoir, Ribagorza, Aragón, Spain

Size: 4 x 15 x 11 cm

Weight: 1196 g