Formula: SrAl3(PO4)(PO3OH)(OH)6
Phosphate containing hydroxyl, plumbogummite group, alunite supergroup, forms series with crandallite and with gorceixite, strontium-bearing mineral
Crystal System: Trigonal
Specific gravity: 3.26 measured, 3.29 calculated
Hardness: 4½ to 5
Streak: White
Colour: White, yellow, honey-yellow, pink, lilac, orange or colourless; colourless in transmitted light
Solubility: Slowly soluble in acids
Common impurities: Ba,F

Sedimentary environments
Hydrothermal environments

Goyazite occurs in granitic pegmatites, in hydrothermal argillic alteration zones, in kaolinitic claystones derived from air-fall volcanic tuff, in sedimentary phosphate deposits, in carbonatites and in detrital deposits, including diamantiferous sands (Mindat, HOM). Associated minerals include apatite, baryte, diamond, herderite, kaolinite, monazite, pyrite and quartz (Mindat).


The type locality is Diamantina, Minas Gerais, Brazil, as placer nodules (Mindat).

At the Alto Benedito pegmatite, Frei Martinho, Borborema mineral province, Paraíba, Brazil, goyazite is associated with herderite, apatite and quartz (HOM).

In the Simplon tunnel, Switzerland, goyazite occurs on anhydrite (Dana).

At the Wigu carbonatite, Tanzania, goyazite is associated with monazite, sphalerite, pyrite, baryte and quartz (HOM).

At the Belaya Kalitva region, Donetz basin, Ukraine, goyazite occurs in limestone with baryte, pyrite and quartz (Dana).

At the Emmons pegmatite, Greenwood, Oxford county, Maine, USA, goyazite has been found as crystals to several mm, also schorl replaced by muscovite has been found with an overgrowth of goyazite and hydroxylherderite. A granular mixture of montebrasite and goyazite has been found. The Emmons pegmatite is an example of a highly evolved boron-lithium-cesium-tantalum enriched pegmatite (R&M 94.6.508).

At the Chickering mine, Cheshire county, New Hampshire, USA, goyazite has been found in cavities adjacent to altered montebrasite, associated with quartz, albite and fluorapatite (R&M 90.5.417).

At the Keyes Mica Quarries, Orange, Grafton County, New Hampshire, USA, the pegmatites are beryl-type rare-element (RE) pegmatites.
The Number 1 mine exposed a pegmatite that shows the most complex zonation and diverse mineralogy of any of the Keyes pegmatites. Six zones are distinguished, as follows, proceeding inward from the margins of the pegmatite:
(1) quartz-muscovite-plagioclase border zone, 2.5 to 30.5 cm thick
(2) plagioclase-quartz-muscovite wall zone, 0.3 to 2.4 metres thick
(3) plagioclase-quartz-perthite-biotite outer intermediate zone, 0.3 to 5.2 metres thick, with lesser muscovite
(4) quartz-plagioclase-muscovite middle intermediate zone, 15.2 to 61.0 cm thick
(5) perthite-quartz inner intermediate zone, 0.9 to 4.6 meters thick
(6) quartz core, 1.5 to 3.0 metres across
The inner and outer intermediate zones contained perthite crystals up to 1.2 meters in size that were altered to vuggy albite-muscovite with fluorapatite crystals. This unit presumably was the source of the albite, muscovite, fluorapatite, quartz and other crystallised minerals found in pieces of vuggy albite rock on the dumps next to the mine.
The middle intermediate zone produced sheet mica with accessory minerals including tourmaline, graftonite, triphylite, vivianite, pyrite, pyrrhotite, and beryl crystals to 30.5 cm long and 12.7 cm across.
Goyazite occurs as white pseudocubic crystals to about 1 mm. One specimen is a cabinet sized specimen with a 6 cm cavity richly lined with microsized goyazite as well as siderite and quartz crystals to several millimeters (R&M 97.4.318).

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