Balestraite is a rare phyllosilicate mineral that forms as thin, platy crystals, primarily known from the alkaline intrusive complex at Mont Saint-Hilaire. Collectors look for its characteristic micaceous habit and pearly luster in association with rare-earth minerals in pegmatite vugs.
Is this balestraite?
4-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 balestraite with a known reference. Balestraite sits at Mohs 2.5-3, softer than the next harder reference, harder than the previous one.
- 2Read the lusterHold the specimen under a strong light. Luster: silky.
- 3Match the color rangeCompare against the expected color range: pale yellow.
- 4Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, micaceous aggregates.
Often confused with
Balestraite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads silky on Balestraite and vitreous to pearly or silky on Muscovite.
How to tell apart: Luster reads silky on Balestraite and pearly to vitreous on Lepidolite.
How to tell apart: Luster reads silky on Balestraite and pearly to waxy when fine-grained on Polylithionite.
Often found alongside balestraite
Minerals reported to co-occur with balestraite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KLi₂VSi₄O₁₂
- Mohs hardness
- 2.5-3
- Density
- 2.946 g/cm³
- Colors
- Luster
- Silky
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Platy crystals, micaceous aggregates
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In manganesiferous beds within the metacherts (prehnite-pumpellyite facies) of an ophiolitic sequence
Where rockhounds find balestraite
Classic worldwide localities
- Cerchiara mine, Eastern Liguria, Italy
Field-hunting tip
Where it forms: In manganesiferous beds within the metacherts (prehnite-pumpellyite facies) of an ophiolitic sequence. If you start seeing hematite, quartz, calcite in float, you are in the right ground. Typical habit: platy crystals, micaceous aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
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Find balestraite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
