Ferro-fluoro-edenite is a rare member of the amphibole group, typically appearing as dark, prismatic to acicular crystals. It is primarily found within alkaline volcanic complexes and contact metamorphic environments. Collectors should note its association with complex volcanic petrology, often found as inclusions or crystals within tuffaceous deposits.
Is this ferro-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 ferro-fluoro-edenite with a known reference. Ferro-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. Ferro-fluoro-edenite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Ferro-fluoro-edenite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: brown, dark green, black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals, fibrous, columnar.
Often confused with
Ferro-fluoro-edenite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Ferro-fluoro-edenite leaves white, Hornblende leaves grayish-white.
How to tell apart: Streak differs — Ferro-fluoro-edenite leaves white, Hastingsite leaves white to light gray.
Often found alongside ferro-fluoro-edenite
Minerals reported to co-occur with ferro-fluoro-edenite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaCa₂Fe₅Si₇AlO₂₂F₂
- Mohs hardness
- 5-6
- Density
- 3.1-3.2 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals, Fibrous, Columnar
- Cleavage
- Perfect Prismatic
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Volcanic Rocks, Skarns
- Typical price
- $20-150 per specimen depending on size
Where rockhounds find ferro-fluoro-edenite
Classic worldwide localities
- Vetralla, Italy
- Biancavilla, Italy
- Franklin, New Jersey
Field-hunting tip
Look in volcanic rocks, skarns country — that is the host setting where ferro-fluoro-edenite typically forms. If you start seeing sanidine, augite, nepheline in float, you are in the right ground. Field specimens usually show a prismatic crystals, fibrous, columnar habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ferro-fluoro-edenite?+
Where is ferro-fluoro-edenite found?+
How much is ferro-fluoro-edenite worth?+
What rocks look like ferro-fluoro-edenite?+
What minerals are found with ferro-fluoro-edenite?+
What kind of rock does ferro-fluoro-edenite form in?+
What is ferro-fluoro-edenite used for?+
Find ferro-fluoro-edenite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
