The open encyclopedia of minerals
Mineralogist.org
Minerals A–ZSearchCollectionsBrowse by PropertyIdentify a SpecimenCompare MineralsLocalities MapGlossaryContribute Search the Database →
Silicate

Ferro-papikeite

NaFe²⁺₂(Fe²⁺₃Al₂)(Si₅Al₃)O₂₂(OH)₂
Hardness6
Crystal systemOrthorhombic
ClassSilicate
Ferro-papikeite specimen

4.4 x 2.4 x 1.6 cm. Sodic-ferrogedrite is a very rare member of the Amphibole Group. Tiny, lustrous, gray-black, bladed grains comprise the spear-point-shaped piece. "In order to better distinguish between amphibole end-member member compositions, the CNMNC has decided to rename sodic-ferrogedrite. The name is not yet (Nov 2012) decided (MINDAT)". MINDAT lists only two localities worldwide for this varietal and neither is in Japan. MINDAT only lists ferro-gedrite for the Kawai Mine. Ex. Eugene Carmichael Collection. Possibly very rare material. — Photo: Robert M. Lavinsky · CC BY-SA 3.0

Ferro-papikeite

Ferro-papikeite is an IMA-recognized mineral species in the silicate class, with the chemical formula NaFe²⁺₂(Fe²⁺₃Al₂)(Si₅Al₃)O₂₂(OH)₂.

It crystallizes in the orthorhombic crystal system (space group Pnma). It is a member of the Amphibole structural group.

Key properties: Mohs hardness 6; specific gravity 3.488; Colorless to very pale brown streak; [Vitreous.] luster; optically biaxial.

IMA symbol Fpa, IMA status: approved, named in 2020.

Found in medium-grade felsic metavolcanic rock.

It is found associated with Quartz, albite, biotite, chlorite.

The prefix identifies an amphibole of the papikeite group with Fe2+ dominant in the C site. Honors James J. Papike (1937-2020).

Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet. Browse more F minerals or help write this entry.