Formula: Mg(PO3OH).3H2O
Hydrated acid phosphate
Specific gravity: 2.10 to 2.11
Hardness: 3 to 3½
Streak: White
Colour: Light Grey to white or colourless, pale brown; colourless in transmitted light.
Solubility: Very slightly soluble in cold water. Readily soluble in dilute hydrochloric acid

Cave deposits

Newberyite is found in caves, formed directly from bat guano (Webmin, HOM).


At the type locality, the Skipton Caves, Mount Widderin, Skipton, Corangamite Shire, Victoria, Australia, newberyite occurs in a bat guano cave deposit associated with hannayite and struvite (Mindat, Dana, HOM).

At the Petrogale Cave, Madura Roadhouse, Dundas Shire, Western Australia, newberyite is associated with biphosphammite (HOM ).

Near Dawson, Yukon, Canada, newberyite from the decaying tooth of a mammoth occurs with struvite and magnesite (Dana).

At Ascension Island, Saint Helena, in the South Atlantic, newberyite has been found in a specimen from the roof of a cavern in a young basalt flow (AM 13.397-401).

At Paoha Island, Mono Lake, Mono county, California, USA, newberyite occurs with monetite and struvite (HOM). The newberyite is a decomposition product of struvite which once formed as large crystals in or immediately below a guano deposit; the original struvite morphology has been preserved by a veneer of monetite (AM 51.1755-1765). Newberyite pseudomorphs after struvite have been found here (KL p197).

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