Romanorlovite is an exceptionally rare mercury-potassium chloride mineral found primarily in volcanic fumaroles. It typically occurs as small, sharp octahedral crystals with a distinct yellow color and high luster, often forming in low-temperature volcanic vent environments.
Is this romanorlovite?
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 romanorlovite with a known reference. Romanorlovite sits at Mohs 1.5-2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Romanorlovite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Romanorlovite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellowish-orange.
- 5Look at form & habitCrystal system: tetragonal.
Often confused with
Romanorlovite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside romanorlovite
Minerals reported to co-occur with romanorlovite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₁₁Cu₉Cl₂₅(OH)₄·2H₂O
- Mohs hardness
- 1.5-2
- Density
- 2.61 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Tetragonal
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Fumarolic Deposits On Volcanic Basalt
Where rockhounds find romanorlovite
Classic worldwide localities
- Tolbachik volcano, Kamchatka, Russia
Field-hunting tip
Look in fumarolic deposits on volcanic basalt country, the host setting where romanorlovite typically forms. If you start seeing sylvite, halite, eritreite in float, you are in the right ground.



