Matulaite is a rare phosphate mineral that typically forms as botryoidal or crust-like coatings in phosphate-rich localities. It is frequently associated with other secondary phosphate minerals like variscite and wavellite, often requiring magnification for accurate identification due to its small size.

Hardness

2.5-3

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrare

Matulaite

Hardness: 2.5-3
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this matulaite?

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 matulaite with a known reference. Matulaite sits at Mohs 2.5-3 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Matulaite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Matulaite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: white, colorless, pale yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: botryoidal, crusts, radial aggregates.

Often confused with

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

How to tell apart: Luster reads vitreous on Matulaite and waxy on Variscite.

How to tell apart: Crandallite is the harder of the two (Mohs 5 vs. 2.5-3).

Compare →

Often found alongside matulaite

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

All properties

Chemical formula: CaAl₇(PO₄)₄(OH)₁₃·18H₂O
Mohs hardness: 2.5-3
Density: 2.44 g/cm³
Colors: White Colorless Pale Yellow
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Botryoidal, Crusts, Radial Aggregates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Phosphate Deposits in Hydrothermal or Weathering Environments
Typical price: $20-150 for micromounts or small specimens

Where rockhounds find matulaite

Classic worldwide localities

Herd Mountain, Alabama, USA
Hellertown, Pennsylvania, USA

Field-hunting tip

Look in phosphate deposits in hydrothermal or weathering environments country — that is the host setting where matulaite typically forms. If you start seeing variscite, wavellite, crandallite in float, you are in the right ground. Field specimens usually show a botryoidal, crusts, radial aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify matulaite?+

Mohs hardness is 2.5-3. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless, pale yellow.

Where is matulaite found?+

Notable localities include Herd Mountain, Alabama, USA; Hellertown, Pennsylvania, USA.

How much is matulaite worth?+

Typical asking prices fall in the range of $20-150 for micromounts or small specimens. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like matulaite?+

Matulaite is most often confused with Wavellite, Variscite, Crandallite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with matulaite?+

Matulaite commonly co-occurs with Variscite, Wavellite, Crandallite, Strengite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does matulaite form in?+

Matulaite typically forms in phosphate deposits in hydrothermal or weathering environments. Working float back to the host body is the standard way to chase a fresh occurrence.

What is matulaite used for?+

Matulaite is used in collector.

Find matulaite on the map

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