Vantasselite is a rare hydrous aluminum phosphate mineral known primarily from its type locality near Vantage, Washington. It typically occurs as delicate, pearly-white, radiating rosettes or micaceous clusters formed within amygdaloidal cavities in basalt. Collectors prize these fragile formations due to their distinct crystal habit and restricted geographic distribution.

Hardness

3.5

Mohs

Luster

Pearly

Streak

White

Transparency

Translucent

mineralrare

Vantasselite

Hardness: 3.5
Luster: Pearly
Streak: White
Transparency: Translucent

Is this vantasselite?

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 vantasselite with a known reference. Vantasselite sits at Mohs 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. Vantasselite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Vantasselite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: white, colorless.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: rosettes of platy crystals, micaceous aggregates.

Often confused with

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

mineral

Wavellite

Mohs 3.5-4

How to tell apart: Luster reads pearly on Vantasselite and vitreous on Wavellite.

How to tell apart: Luster reads pearly on Vantasselite and waxy on Variscite.

Compare →

Often found alongside vantasselite

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

All properties

Chemical formula: Al₄(PO₄)₃(OH)₃·9H₂O
Mohs hardness: 3.5
Density: 2.8 g/cm³
Colors: White Colorless
Streak: White
Luster: Pearly
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Rosettes of Platy Crystals, Micaceous Aggregates
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Sedimentary Basalt Cavities
Typical price: $20-100 per specimen depending on size and quality

Where rockhounds find vantasselite

Classic worldwide localities

Vantage, Washington, USA

Field-hunting tip

Look in sedimentary basalt cavities country — that is the host setting where vantasselite typically forms. If you start seeing quartz, chalcedony, hematite in float, you are in the right ground. Field specimens usually show a rosettes of platy crystals, micaceous aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify vantasselite?+

Mohs hardness is 3.5. It typically shows a pearly luster. The streak is white. Common colors include white, colorless.

Where is vantasselite found?+

Notable localities include Vantage, Washington, USA.

How much is vantasselite worth?+

Typical asking prices fall in the range of $20-100 per specimen depending on size and quality. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like vantasselite?+

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

What minerals are found with vantasselite?+

Vantasselite commonly co-occurs with Quartz, Chalcedony, Hematite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does vantasselite form in?+

Vantasselite typically forms in sedimentary basalt cavities. Working float back to the host body is the standard way to chase a fresh occurrence.

What is vantasselite used for?+

Vantasselite is used in collector.

Find vantasselite on the map

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