Friedelite is a rare manganese silicate that typically forms in metamorphosed manganese-rich deposits. It is most recognizable by its distinct pink to brownish-red color and perfect basal cleavage, often appearing as tabular crystals or in massive form alongside other manganese minerals.
Is this friedelite?
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 friedelite with a known reference. Friedelite sits at Mohs 4-5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale rose.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous, pearly on basal plane.
- 4Match the color rangeCompare against the expected color range: brown, brown red, yellow, light pink, dark red.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: massive, tabular.
Often confused with
Friedelite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside friedelite
Minerals reported to co-occur with friedelite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mn₈Si₆O₁₅(OH)₁₀
- Mohs hardness
- 4-5
- Density
- 3.04-3.06 g/cm³
- Streak
- Pale rose
- Luster
- Vitreous, pearly on basal plane
- Transparency
- Translucent to transparent
- Crystal system
- Monoclinic
- Crystal habit
- Massive, tabular
- Cleavage
- Perfect on {0001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In metamorphosed Mn-Fe deposits
Where rockhounds find friedelite
Classic worldwide localities
- Franklin and Sterling Hill, Ogdensburg, Sussex Co., New Jersey, and the Sunnyside mine, Silverton district, San Juan Co., Colorado, USA
- Adervielle, Louron Valley, Hautes-Pyrénées, and Costabonne, Pyrénées-Orientales, France
- Harstigen mine, near Persberg, Värmland, and in the Sjö mine, near Grythyttan, Örebro, Sweden
- Ködnitz Valley, Tirol, Austria
- Dshumart and Kamya, Atasui region, Kazakhstan
- Wessels and N'Chwaning mines, near Kuruman, Cape Province, South Africa
Field-hunting tip
Where it forms: In metamorphosed Mn-Fe deposits. If you start seeing rhodochrosite, alabandite, franklinite in float, you are in the right ground. Typical habit: massive, tabular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify friedelite?+
Where is friedelite found?+
What rocks look like friedelite?+
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Find friedelite on the map
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