Belomarinaite is a rare potassium-sodium sulfate mineral typically found as a volcanic sublimate in fumaroles. It most commonly appears as small, colorless to white tabular crystals or thin crusts associated with other high-temperature volcanic minerals. It is highly soluble in water and requires careful storage in a humidity-controlled environment.

Hardness

2-3

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Belomarinaite

Hardness: 2-3
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this belomarinaite?

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 belomarinaite with a known reference. Belomarinaite sits at Mohs 2-3, 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, white.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: tabular crystals, crusts, or efflorescences.

Often confused with

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

Often found alongside belomarinaite

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

All properties

Chemical formula: NaKSO₄
Mohs hardness: 2-3
Density: 2.63 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Tabular crystals, crusts, or efflorescences
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: volcanic fumaroles

Where rockhounds find belomarinaite

Classic worldwide localities

Tolbachik volcano, Kamchatka, Russia

Field-hunting tip

Where it forms: volcanic fumaroles. If you start seeing aphthitalite, thenardite, sylvite in float, you are in the right ground. Typical habit: tabular crystals, crusts, or efflorescences. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify belomarinaite?+

Mohs hardness is 2-3. Luster: vitreous. The streak is white. Common colors include colorless, white.

Where is belomarinaite found?+

Notable localities include Tolbachik volcano, Kamchatka, Russia.

What rocks look like belomarinaite?+

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

What minerals are found with belomarinaite?+

Belomarinaite commonly co-occurs with Aphthitalite, Thenardite, Sylvite, Halite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does belomarinaite form in?+

Where it forms: volcanic fumaroles. Working float back to the host body is the standard way to chase a fresh occurrence.

What is belomarinaite used for?+

Belomarinaite is used in collector.

Find belomarinaite on the map

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