Lasalite is a rare hydrated sodium magnesium vanadate that typically forms as an efflorescent crust in oxidized vanadium-bearing sandstone deposits. Collectors should look for characteristic yellowish, secondary coatings in arid environments, often requiring magnification for accurate identification due to their delicate habit.
Is this lasalite?
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 lasalite with a known reference. Lasalite sits at Mohs 1, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: yellow, yellow orange.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: efflorescences, prismatic.
Often confused with
Lasalite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Pascoite is the harder of the two (Mohs ~2.5 vs. 1); streak differs, so Lasalite leaves yellow, Pascoite leaves cadmium-yellow; luster reads adamantine on Lasalite and vitreous to subadamantine on Pascoite.
How to tell apart: Sherwoodite is the harder of the two (Mohs ~2 vs. 1); streak differs, so Lasalite leaves yellow, Sherwoodite leaves pale blue; luster reads adamantine on Lasalite and vitreous to earthy on Sherwoodite.
Often found alongside lasalite
Minerals reported to co-occur with lasalite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- [Mg(H₂O)₆]₂Na₂[V₁₀O₂₈](H₂O)₈
- Mohs hardness
- 1
- Density
- 2.38 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Adamantine
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Efflorescences, prismatic
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As efflorescences in oxidized portions of paleochannel uranium vanadium deposits of the Colorado Plateau type
Where rockhounds find lasalite
Classic worldwide localities
- Vanadium Queen Mine, La Sal district, and Firefly-Pigmay and Blue Cap mines, Utah, USA
- Yellow Cat district, Grand County, Utah, USA
- Colorado Plateau, e.g
Field-hunting tip
Where it forms: As efflorescences in oxidized portions of paleochannel uranium vanadium deposits of the Colorado Plateau type. If you start seeing rossite, dickthomssenite, hewettite in float, you are in the right ground. Typical habit: efflorescences, prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify lasalite?+
Where is lasalite found?+
Is lasalite safe to handle?+
What rocks look like lasalite?+
What minerals are found with lasalite?+
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Find lasalite on the map
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