Anhydrite, Hematite

St Gotthard basis tunnel, NEAT Construction site, Amsteg, Reuss Valley, Uri, Switzerland

5,1×3,2×1,7 cm.

An exquisite and rare cluster composed by elongated Anhydrite crystals showcases parallel striations along their length, adorned with a pearly luster and a delicate pink-magenta hue. The internal transparency of this specimen is exceptionally captivating, enhanced by the presence of brilliant Hematite that gracefully covers portions of the surface, providing a delightful aesthetic bonus.

Anhydrite is a classic alpine mineral but rarely seen in fine specimens and highly sought after by exigent collectors. The Gotthard Base Tunnel, a railway tunnel through the Swiss Alps, officially opened on June 1, 2016, with full service commencing on December 11, 2016. This specimen was unearthed during the construction of the renowned NEAT tunnel in the St Gotthard Pass. The tunneling project unexpectedly encountered few pockets containing large crystals of this rare Alpine classic, now highly prized. This piece has all the characteristics to be considered a rare, aesthetic and highly representative specimen.

examples of ANHYDRITE from SWITZERLAND :

Anhydrite is a mineral of anhydrous calcium sulfate (CaSO₄), discovered in 1794 in a salt mine near Hall in Tirol, and easily transformable into the most common Gypsum (CaSO4*2H2O) if exposed to the water. Distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses. Anhydrite is most frequently found in evaporite deposits with gypsum, by precipitation of calcium sulfate from saturated seawater when the solution contains an excess of sodium or potassium chloride and the temperature is above 40 °C.