Varennesite is an exceptionally rare sodium manganese silicate found almost exclusively in the alkaline pegmatites of Mont Saint-Hilaire. Collectors typically look for small, transparent to translucent tabular crystals associated with other rare minerals in vugs within intrusive igneous rocks.
Is this varennesite?
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 varennesite with a known reference. Varennesite sits at Mohs 4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: pale brownish yellow, orange.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: euhedral crystals, tabular.
Often confused with
Varennesite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside varennesite
Minerals reported to co-occur with varennesite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₈Mn₂Si₁₀O₂₅(OH,Cl)₂·12H₂O
- Mohs hardness
- 4
- Density
- 2.31 g/cm³
- Colors
- Pale brownish yellowOrange
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Euhedral crystals, tabular
- Cleavage
- Good on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As a primary, late-stage mineral in a sill
Where rockhounds find varennesite
Classic worldwide localities
- Demix-Varennes quarry, which lies between the villages of Varennes and Saint-Amable, in Vercheres County, Quebec (type locality)
Field-hunting tip
Where it forms: As a primary, late-stage mineral in a sill. If you start seeing aegirine, albite, analcime in float, you are in the right ground. Typical habit: euhedral crystals, tabular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify varennesite?+
Where is varennesite found?+
What rocks look like varennesite?+
What minerals are found with varennesite?+
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Find varennesite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
