Picture width 1.5 mm. Collection and photograph Christian Rewitzer. From Långban, Filipstad, Värmland, Sweden — Photo: Christian Rewitzer · CC BY-SA 3.0
Aminoffite
A silicate named in 1937 for Gregori Aminoff — the Swedish mineralogist and artist who pioneered Långban mineralogy.
Intro adapted from Wikipedia (CC BY-SA).
Aminoffite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₃(BeOH)₂Si₃O₁₀.
It crystallizes in the tetragonal crystal system (space group I4/mmm).
Key properties: Mohs hardness 5.5–6; specific gravity 2.94; Vitreous luster; optically uniaxial.
IMA symbol Amf, grandfathered status — known before the IMA’s founding, named in 1937.
Found in cavities in massive magnetite (Lº angban, Sweden); in fluorite veins at the contact between marbles and \hornblende" granites in association with hastingsite nepheline syenites (Dugdinsk massif, Russia).
It is found associated with Magnetite, goethite (Lº angban, Sweden); fluorite (Russia).
The mineral was named to honor Dr. Gregori Aminoff (1883–1947), Swedish mineralogist and expert on Lº angban mineralogy, associated with the Riksmuseum, Stockholm, Sweden.