Magnesio-ferri-fluoro-hornblende is a complex amphibole group mineral characterized by high fluorine content. It typically forms dark, prismatic crystals within medium-to-high grade metamorphic rocks. Identification usually requires X-ray diffraction or chemical analysis due to its visual similarity to other common hornblende species.
Is this magnesio-ferri-fluoro-hornblende?
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 magnesio-ferri-fluoro-hornblende with a known reference. Magnesio-ferri-fluoro-hornblende sits at Mohs 5-6, softer than the next harder reference, harder than the previous one.
- 2Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 3Match the color rangeCompare against the expected color range: dark brown.
- 4Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals.
Often confused with
Magnesio-ferri-fluoro-hornblende vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside magnesio-ferri-fluoro-hornblende
Minerals reported to co-occur with magnesio-ferri-fluoro-hornblende. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- □Ca₂(Mg₄Fe)(Si₇Al)O₂₂F₂
- Mohs hardness
- 5-6
- Density
- 3.315 g/cm³
- Colors
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic crystals
- Cleavage
- Perfect on {110}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In vugs in a welded tuff
Where rockhounds find magnesio-ferri-fluoro-hornblende
Classic worldwide localities
- Coast road, ~5.5 km northeast of Portoscuso, Cagliari, Sardinia, Italy
Field-hunting tip
Where it forms: In vugs in a welded tuff. If you start seeing tridymite, todorokite, magnetite in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify magnesio-ferri-fluoro-hornblende?+
Where is magnesio-ferri-fluoro-hornblende found?+
What rocks look like magnesio-ferri-fluoro-hornblende?+
What minerals are found with magnesio-ferri-fluoro-hornblende?+
What kind of rock does magnesio-ferri-fluoro-hornblende form in?+
What is magnesio-ferri-fluoro-hornblende used for?+
Find magnesio-ferri-fluoro-hornblende on the map
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