:Locality: Kopeisk, Chelyabinsk Oblast', Urals Region, Russian Federation Size: 0.8 × 0.6 × 0.6 cm Description: Kremersite is a very rare complex halide, very deliquescent, that is why it is protected sealed in a glass capsule. Visible crystals, transparent and with an intense red color. From the coal mine Nr. 50 of this Russian locality known for more than 40 new species formed on spontaneous burning coal dumps and are known to rage for many years or decades, forming many rare high-temperature minerals. — Photo: Joan Rosell , from rosellminerals.com · CC BY-SA 4.0
Kremersite
A rare brown-red hydrated iron-ammonium-potassium chloride crystallizing in the orthorhombic system.
Intro adapted from Wikipedia (CC BY-SA).
Kremersite is an IMA-recognized mineral species in the halide class, with the chemical formula (NH₄)₂Fe³⁺Cl₅·H₂O.
It crystallizes in the orthorhombic crystal system (space group Pnma).
Key properties: specific gravity 2.175; Vitreous luster.
IMA symbol Km, grandfathered status — known before the IMA’s founding, named in 1853.
Occurs as sublimates around fumaroles.
It is found associated with Erythrosiderite, molysite, hematite (Vesuvius, Italy); erythrosiderite (Kliuchevsky volcano, Russia).
The mineral was named to honor the German chemist, Peter Kremers (1827–?), who analyzed the mineral.