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

Foggite

CaAl(PO₄)(OH)₂·H₂O
Hardness4
Crystal systemOrthorhombic
ClassPhosphate
Foggite specimen

Foggite Locality: Palermo No. 1 Mine (Palermo No. 1 pegmatite; Hartford Mine; GE Mine), Groton, Grafton Co., New Hampshire, USA Dimensions: 2.6 cm x 1.8 cm x 1.3 cm A cool and rare representative specimen featuring orange-yellow groups of the calcium aluminum phosphate, foggite from Pod No. 3 of the Palermo No. 1 Mine. Foggite is named after Forrest F. Fogg, a mineral collector of Penacook, New Hampshire, who provided the first material. This mineral is only found in four world localities, and the most famous material is from the Palermo No. 1 Mine. This particular piece was mined in 1975. For reference, the label states that there is an unknown mineral on the piece as well. — Photo: Robert M. Lavinsky · CC BY-SA 3.0

Foggite

Foggite is an IMA-recognized mineral species in the phosphate class, with the chemical formula CaAl(PO₄)(OH)₂·H₂O.

It crystallizes in the orthorhombic crystal system (space group A2_122).

Key properties: Mohs hardness 4; specific gravity 2.78; optically biaxial.

IMA symbol Fgg, IMA status: approved, named in 1973.

A secondary mineral, probably formed at < 300 ° C, in complex granite pegmatites.

It is found associated with Carbonate-apatite, childrenite, whitlockite, montebrasite, siderite, quartz.

The mineral was named to honor Forrest F. Fogg (1920–), mineral collector of Penacook, New Hampshire, USA, who provided the first material.

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.