Landesite Locality: Berry-Havey Quarry, Poland, Androscoggin Co., Maine ( Locality at mindat.org ) This extremely rare and important little crystal is approx 3mm in size. It was a gift from Harvard to the AMNH in the mid-1900s (label included) and one should be able to reasonably suppose that, since the type material was residing at Harvard, this crystal comes from the type material or at least the same pocket - or why bother to give it as a carefully catalogued gift to their colleague? Ex AMNH exchanged into the collection of dealer/collector Lawrence Conklin. 0.3 x 0.25 x 0.25 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Landesite
Landesite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Mn²⁺₉Fe³⁺₃(PO₄)₈(OH)₃·9H₂O.
It crystallizes in the orthorhombic crystal system (space group Pbna). It is a member of the Reddingite structural group.
Key properties: Mohs hardness 3–3.5; specific gravity 3.026; optically biaxial.
IMA symbol Lds, IMA status: approved, named in 1930.
Replacing reddingite in a complex granite pegmatite (Berry quarry, Maine, USA).
It is found associated with Reddingite, lithiophilite, rhodochrosite, eosphorite, fairfieldite, apatite (Berry quarry, Maine, USA).
The mineral was named to honor Dr. Kenneth Knight Landes (1899–1984), Professor of Geology, University of Michigan, Ann Arbor, Michigan, USA, for his study of Maine pegmatites.