Jeffreyite is a rare beryllium-bearing mineral first identified at the famous Jeffrey Mine in Quebec. It typically forms as delicate, acicular, or prismatic crystals and is prized for its notable fluorescence under ultraviolet light.
Is this jeffreyite?
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 jeffreyite with a known reference. Jeffreyite sits at Mohs 5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Jeffreyite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Jeffreyite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, pale yellow.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: prismatic crystals, acicular.
Often confused with
Jeffreyite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside jeffreyite
Minerals reported to co-occur with jeffreyite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Ca,Na)₂(Be,Al)Si₂O₇
- Mohs hardness
- 5
- Density
- 2.98 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Tetragonal
- Crystal habit
- Prismatic Crystals, Acicular
- Cleavage
- Distinct On {001}
- Fluorescence
- Bright White/yellow Under SW UV
- Rarity
- Rare
- Uses
- Collector, Scientific Research
- Host rock
- Altered Igneous Rocks and Metamorphic Contact Zones
- Typical price
- $50-300 per specimen
Where rockhounds find jeffreyite
Classic worldwide localities
- Jeffrey Mine, Quebec, Canada
- Mont Saint-Hilaire, Quebec, Canada
Field-hunting tip
Look in altered igneous rocks and metamorphic contact zones country — that is the host setting where jeffreyite typically forms. If you start seeing grossular, vesuvianite, wollastonite in float, you are in the right ground. Field specimens usually show a prismatic crystals, acicular habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find jeffreyite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
