Kolfanite is a rare iron-rich member of the garnet group typically found in contact metamorphic skarn zones. It is characterized by its distinct brownish-yellow dodecahedral crystals and is highly prized by mineral collectors specializing in rare garnet species.
Is this kolfanite?
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 kolfanite with a known reference. Kolfanite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: orange.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: red, yellow, orange.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: flattened crystals, compact radiating nodules.
Often confused with
Kolfanite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Andradite is the harder of the two (Mohs 6.5-7 vs. 2.5); streak differs, so Kolfanite leaves orange, Andradite leaves white.
How to tell apart: Grossular is the harder of the two (Mohs 6.5-7 vs. 2.5); streak differs, so Kolfanite leaves orange, Grossular leaves white; luster reads adamantine on Kolfanite and vitreous to resinous on Grossular.
Often found alongside kolfanite
Minerals reported to co-occur with kolfanite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂Fe₃O₂(AsO₄)₃·2H₂O
- Mohs hardness
- 2.5
- Density
- 3.3 g/cm³
- Streak
- Orange
- Luster
- Adamantine
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Flattened crystals, compact radiating nodules
- Cleavage
- One, parallel to flattening
- Rarity
- Rare
- Uses
- Collector
- Host rock
- An alteration product of holtite in a hydrothermally altered granite pegmatite
Where rockhounds find kolfanite
Classic worldwide localities
- Mt. Vasin-Myl’k, Voron’i massif, Kola Peninsula, Russia
Field-hunting tip
Where it forms: An alteration product of holtite in a hydrothermally altered granite pegmatite. If you start seeing mitridatite, arseniosiderite, laueite in float, you are in the right ground. Typical habit: flattened crystals, compact radiating nodules. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify kolfanite?+
Where is kolfanite found?+
Is kolfanite safe to handle?+
What rocks look like kolfanite?+
What minerals are found with kolfanite?+
What kind of rock does kolfanite form in?+
What is kolfanite used for?+
Find kolfanite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
