Fluorlamprophyllite is a rare member of the lamprophyllite group found in alkaline complexes. It typically appears as thin, brown, blade-like or needle-like crystals embedded within nepheline syenite matrices. Collectors value it for its sharp, distinct crystal form despite its rarity.
Is this fluorlamprophyllite?
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 fluorlamprophyllite with a known reference. Fluorlamprophyllite sits at Mohs ~3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: brownish orange.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular crystals, bladed aggregates.
Often confused with
Fluorlamprophyllite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads adamantine on Fluorlamprophyllite and submetallic on cleavages on Lamprophyllite.
How to tell apart: Bafertisite is the harder of the two (Mohs ~5 vs. ~3); streak differs, so Fluorlamprophyllite leaves pale yellow, Bafertisite leaves white; luster reads adamantine on Fluorlamprophyllite and vitreous on Bafertisite.
Often found alongside fluorlamprophyllite
Minerals reported to co-occur with fluorlamprophyllite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (SrNa)Ti₂Na₃Ti(Si₂O₇)₂O₂F₂
- Mohs hardness
- ~3
- Density
- 3.484 g/cm³
- Colors
- Streak
- Pale yellow
- Luster
- Adamantine
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular crystals, bladed aggregates
- Cleavage
- Perfect on {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Embedded in nepheline syenite in an alkaline massif
Where rockhounds find fluorlamprophyllite
Classic worldwide localities
- Poços de Caldas alkaline massif, Morro do Serrote, Minas Gerais, Brazil
Field-hunting tip
Where it forms: Embedded in nepheline syenite in an alkaline massif. If you start seeing aegirine, analcime, natrolite in float, you are in the right ground. Typical habit: acicular crystals, bladed aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify fluorlamprophyllite?+
Where is fluorlamprophyllite found?+
What rocks look like fluorlamprophyllite?+
What minerals are found with fluorlamprophyllite?+
What kind of rock does fluorlamprophyllite form in?+
What is fluorlamprophyllite used for?+
Find fluorlamprophyllite on the map
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