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.
Is this belomarinaite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch belomarinaite with a known reference. Belomarinaite sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Belomarinaite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Belomarinaite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: colorless, white.
- 5Look at form & habitCrystal 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
- 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
- Typical price
- $50-300+ depending on matrix quality
Where rockhounds find belomarinaite
Classic worldwide localities
- Tolbachik volcano, Kamchatka, Russia
Field-hunting tip
Look in volcanic fumaroles country — that is the host setting where belomarinaite typically forms. If you start seeing aphthitalite, thenardite, sylvite in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts, or efflorescences habit, so train your eye for that shape before scanning the outcrop.





