Fluoro-edenite is a rare member of the amphibole group characterized by its sodium and fluorine-rich chemistry. It typically occurs as elongated prismatic or fibrous crystals in altered skarn environments and is notable for its historical association with health hazards in volcanic areas like Sicily.
Is this fluoro-edenite?
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 fluoro-edenite with a known reference. Fluoro-edenite sits at Mohs 5-6, 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: vitreous to greasy.
- 4Match the color rangeCompare against the expected color range: intense yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular, fibrous, prismatic.
Often confused with
Fluoro-edenite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Fluoro-edenite leaves yellow, Tremolite leaves white.
How to tell apart: Streak differs, so Fluoro-edenite leaves yellow, Actinolite leaves white.
How to tell apart: Streak differs, so Fluoro-edenite leaves yellow, Edenite leaves white.
Often found alongside fluoro-edenite
Minerals reported to co-occur with fluoro-edenite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaCa₂Mg₅(Si₇Al)O₂₂F₂
- Mohs hardness
- 5-6
- Density
- 3.0-3.2 g/cm³
- Colors
- Intense yellow
- Streak
- Yellow
- Luster
- Vitreous to greasy
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular, fibrous, prismatic
- Cleavage
- Perfect on {110}
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- Gray-red altered benmoreitic lavas and other andesites crystallized from late-stage hydrothermal fluids
Where rockhounds find fluoro-edenite
Classic worldwide localities
- Etnean Volcanic Complex, Catania, Italy., Ishigamiyama lava dome of the Kimpo volcano, Kumamoto, southwest Japan (type locality)
Field-hunting tip
Where it forms: Gray-red altered benmoreitic lavas and other andesites crystallized from late-stage hydrothermal fluids. If you start seeing calcite, diopside, garnet in float, you are in the right ground. Typical habit: acicular, fibrous, prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify fluoro-edenite?+
Where is fluoro-edenite found?+
Is fluoro-edenite safe to handle?+
What rocks look like fluoro-edenite?+
What minerals are found with fluoro-edenite?+
What kind of rock does fluoro-edenite form in?+
What is fluoro-edenite used for?+
Find fluoro-edenite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
