Lautarite
Anhydrous calcium iodate — a mineral of Chilean nitrate deposits, companion to the hydrated form bruggenite.
Intro adapted from Wikipedia (CC BY-SA).
Lautarite is an IMA-recognized mineral species in the iodate class, with the chemical formula Ca(IO₃)₂.
It crystallizes in the monoclinic crystal system (space group P2_1/n).
Key properties: Mohs hardness 3.5–4; specific gravity 4.59; typically colorless or white or yellow; white streak; vitreous luster; optically biaxial.
IMA symbol Ltr, grandfathered status — known before the IMA’s founding, named in 1891.
Coating fractures or embedded in gypsum in the nitrate deposits.
It is found associated with Gypsum, brüggenite, dietzeite, nitratine, anhydrite, hydroboracite, halite.
The name refers to its occurrence at Oficina Lautaro, Chile.
Collections: Rare & Remarkable, Collector Favorites.