Fluellite is a mineral with the chemical formula Al₂(PO₄)F₂(OH)•7H₂O. The name is from its chemical composition, being a fluate of alumine (French).

It was first described in 1824 for an occurrence in the Stenna Gwyn Mine, St Stephen-in-Brannel

St Stephen-in-Brannel

St Stephen-in-Brannel is a civil parish and village in central Cornwall, United Kingdom. St Stephen village is four miles west of St Austell on the southern edge of Cornwall's china clay district.In medieval times the parish lay within the royal manor of Brannel...

, St Austell

St Austell

St Austell is a civil parish and a major town in Cornwall, England, United Kingdom. It is situated on the south coast approximately ten miles south of Bodmin and 30 miles west of the border with Devon at Saltash...

 District, Cornwall

Cornwall

Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

.

It is a rare secondary mineral found in complex granite

Granite

Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

 pegmatite

Pegmatite

A pegmatite is a very crystalline, intrusive igneous rock composed of interlocking crystals usually larger than 2.5 cm in size; such rocks are referred to as pegmatitic....

s where it forms by weathering

Weathering

Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...

 of earlier phosphate minerals. It is found in association with fluorapatite

Fluorapatite

Fluorapatite, often with the alternate spelling of fluoroapatite, is a mineral with the formula Ca53F . Fluorapatite is a hard crystalline solid. Although samples can have various color , the pure mineral is colorless as expected for a material lacking transition metals...

, wavellite

Wavellite

Wavellite is a phosphate mineral with formula Al323·5H2O.It normally occurs as translucent green radial or spherical clusters.-Discovery and occurrence:...

, phosphosiderite, strengite, aldermanite

Aldermanite

Aldermanite is a rare hydrated phosphate mineral with formula Mg5Al12822·32H2O....

, cacoxenite

Cacoxenite

Cacoxenite is an iron aluminium phosphate mineral with formula: Fe3+24Al17O612·17. It is associated with iron ores. The name comes from the Greek κăκός for "bad" or "evil" and ξένος for "guest" because the phosphorus content of cacoxenite lessens the quality of iron smelted from ore containing...

, variscite

Variscite

Variscite is a hydrated aluminium phosphate mineral |H2O]]). It is a relatively rare phosphate mineral. It is sometimes confused with turquoise; however, variscite is usually greener in color....

, turquoise

Turquoise

Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl648·4. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue...

, fluorite

Fluorite

Fluorite is a halide mineral composed of calcium fluoride, CaF2. It is an isometric mineral with a cubic habit, though octahedral and more complex isometric forms are not uncommon...

 and quartz

Quartz

Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

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