Keckite , Strunzite , Rockbridgeite Size: 3.4 cm × 2.4 cm × 1.8 cm Locality: Hagendorf South Pegmatite (Waidhaus), Bavaria, Germany Description: Hagendorf pegmatites are well known for phosphate species. Strunzite and rockbridgeite are more or less common, but keckite is very rare. In this specimen we can see some defined crystals of keckite, with tabular forms, transparence and orange color. Acompanied by strunzite white needles and black rockbridgeite-frondellite. In this specimen we have two species from the Type Locality: keckite and strunzite. — Photo: Joan Rosell , from rosellminerals.com · CC BY-SA 4.0
Keckite
Keckite is an IMA-recognized mineral species in the phosphate class, with the chemical formula CaMn(Fe³⁺,Mn)₂Fe³⁺₂(PO₄)₄(OH)₃·7H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/a). It is a member of the Jahnsite structural group.
Key properties: Mohs hardness 4.5; specific gravity 2.6; Dull luster; optically biaxial.
IMA symbol Kec, IMA status: approved, named in 1977.
A weathering product of phosphate minerals in a complex granite pegmatite.
It is found associated with Rockbridgeite, phosphophyllite, scholzite, fairfieldite, vivianite, reddingite, huréaulite, strengite, apatite.
The mineral was named to honor Erich Keck, Etzenricht, Germany, collector of Hagendorf minerals.