Gedrite is an orthorhombic amphibole typically found in regional metamorphic rocks such as amphibolites and gneisses. Collectors prize its distinct radiating fibrous or bladed habit, often occurring in association with cordierite and garnet.
Is this gedrite?
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 gedrite with a known reference. Gedrite 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. Gedrite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Gedrite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: brown, gray, green, white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: fibrous, massive, bladed, or radiating prisms.
Often confused with
Gedrite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside gedrite
Minerals reported to co-occur with gedrite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Mg,Fe²⁺)₂(Mg,Fe²⁺)₄Al₂Si₆O₂₂(OH)₂
- Mohs hardness
- 5-6
- Density
- 3.1-3.6 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Fibrous, Massive, Bladed, Or Radiating Prisms
- Cleavage
- Perfect Prismatic
- Rarity
- Uncommon
- Uses
- Collector, Scientific Study
- Host rock
- Metamorphic Rocks
- Typical price
- $10-60 thumbnail, $50-200 cabinet specimen
Where rockhounds find gedrite
Classic worldwide localities
- Gedrite, France
- Massachusetts, USA
- New Hampshire, USA
- Sweden
- Finland
Field-hunting tip
Look in metamorphic rocks country — that is the host setting where gedrite typically forms. If you start seeing garnet, cordierite, staurolite in float, you are in the right ground. Field specimens usually show a fibrous, massive, bladed, or radiating prisms habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find gedrite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
