Vyalsovite is a rare hydrous calcium magnesium aluminum sulfate carbonate mineral discovered in the Kola Peninsula. It typically forms as thin tabular crystals or radial aggregates within alkaline pegmatites. Collectors primarily find it as a rare species of interest in mineralogical systematic collections.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Vyalsovite

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

No image

Is this vyalsovite?

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 vyalsovite with a known reference. Vyalsovite 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. Vyalsovite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Vyalsovite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: white, colorless.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: tabular crystals, aggregates.

Often confused with

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

mineral

Hydrocalumite

Mohs 2

How to tell apart: Vyalsovite is noticeably harder (Mohs 3.5 vs. 2); luster reads vitreous on Vyalsovite and pearly on Hydrocalumite.

How to tell apart: Vyalsovite is noticeably harder (Mohs 3.5 vs. 2).

Compare →

Often found alongside vyalsovite

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

All properties

Chemical formula: Ca₄Mg₄Al₂(OH)₁₂SO₄(CO₃)·2H₂O
Mohs hardness: 3.5
Density: 2.44 g/cm³
Colors: White Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Tabular Crystals, Aggregates
Cleavage: Good
Rarity: Rare
Uses: Collector
Host rock: Alkaline Igneous Rocks
Typical price: $50-200 per specimen

Where rockhounds find vyalsovite

Classic worldwide localities

Vyals Lake, Kola Peninsula, Russia

Field-hunting tip

Look in alkaline igneous rocks country — that is the host setting where vyalsovite typically forms. If you start seeing hydrotalcite, calcite, thaumasite in float, you are in the right ground. Field specimens usually show a tabular crystals, aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify vyalsovite?+

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

Where is vyalsovite found?+

Notable localities include Vyals Lake, Kola Peninsula, Russia.

How much is vyalsovite worth?+

Typical asking prices fall in the range of $50-200 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like vyalsovite?+

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

What minerals are found with vyalsovite?+

Vyalsovite commonly co-occurs with Hydrotalcite, Calcite, Thaumasite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does vyalsovite form in?+

Vyalsovite typically forms in alkaline igneous rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is vyalsovite used for?+

Vyalsovite is used in collector.

Find vyalsovite on the map

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