Euchlorine

Euchlorine (KNaCu3(SO4)3O) is a rare emerald-green sulfate mineral found naturally occurring as a sublimate in fumaroles around volcanic eruptions. It was first discovered in fumaroles of the 1868 eruption at Mount Vesuvius in Campania, Italy by Arcangelo Scacchi. The name 'euchlorine' comes from the Greek word εΰχλωρος meaning "pale green" in reference to the mineral's color, other reported spellings include euclorina, euchlorin, and euchlorite. The ideal formula of euchlorine is KNaCu3(SO4)3O though calcium (Ca) and magnesium (Mg) occasionally substitute into the crystal lattice. Euchlorine is structurally related to puninite (Na2Cu3(SO4)3O) and fedotovite (K2Cu3(SO4)3O), all of which are included in the euchlorine group of minerals. One of the distinguishing physical properties helpful for identifying euchlorine in hand sample is its streak, which is a pistachio-green color. If trying to find euchlorine in the field, wear protective clothing as the volcanic fumaroles around which it occurs can be very hot (approximately 300 to 650 °C, 580 to 1200 °F) and can cause severe steam burns if not adequately protected.