Newberyite is a rare magnesium phosphate mineral typically formed by the reaction of magnesium-rich rocks with bat guano in cave environments. It commonly appears as small, colorless or white tabular crystals that are soft and brittle. Collectors primarily source it from classic localities like the Skipton Caves in Australia.

Hardness

3-3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Newberyite

Hardness: 3-3.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this newberyite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch newberyite with a known reference. Newberyite sits at Mohs 3-3.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: colorless, gray brown, grayish.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: tabular crystals, massive, granular.

Often confused with

Newberyite vs. its common look-alikes, and how to tell them apart in the field.

mineral

Struvite

Mohs 2

How to tell apart: Newberyite is noticeably harder (Mohs 3-3.5 vs. 2).

Often found alongside newberyite

Minerals reported to co-occur with newberyite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: MgHPO₄·3H₂O
Mohs hardness: 3-3.5
Density: 2.10 g/cm³
Colors: Colorless Gray brown Grayish
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Tabular crystals, massive, granular
Cleavage: {010}, perfect; {001}, imperfect
Rarity: Rare
Uses: Collector
Host rock: In caves, formed directly from bat guano

Where rockhounds find newberyite

Classic worldwide localities

Paoha Island, Mono Lake, Mono Co., California, USA
Skipton lava tube caves, 40 km southwest of Ballarat, Victoria, and the Petrogale Cave, near Madura, Western Australia
Niah Great Cave, Sarawak, Malaysia
Mt. Erebus, Victoria Land, Antarctica
Reunion Island, Indian Ocean
Ascension Island, south Atlantic

Field-hunting tip

Where it forms: In caves, formed directly from bat guano. If you start seeing hannayite, struvite, biphosphammite in float, you are in the right ground. Typical habit: tabular crystals, massive, granular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify newberyite?+

Mohs hardness is 3-3.5. Luster: vitreous. The streak is white. Common colors include colorless, gray brown, grayish.

Where is newberyite found?+

Notable localities include Paoha Island, Mono Lake, Mono Co., California, USA; Skipton lava tube caves, 40 km southwest of Ballarat, Victoria, and the Petrogale Cave, near Madura, Western Australia; Niah Great Cave, Sarawak, Malaysia; Mt. Erebus, Victoria Land, Antarctica; Reunion Island, Indian Ocean.

What rocks look like newberyite?+

Newberyite is most often confused with Struvite, Brushite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with newberyite?+

Newberyite commonly co-occurs with Hannayite, Struvite, Biphosphammite, Monetite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does newberyite form in?+

Where it forms: In caves, formed directly from bat guano. Working float back to the host body is the standard way to chase a fresh occurrence.

What is newberyite used for?+

Newberyite is used in collector.

Find newberyite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.