Nenadkevichite is a rare niobate-silicate mineral typically found in highly evolved alkaline pegmatites. It forms distinct prismatic or tabular crystals, often exhibiting a honey-yellow or brownish hue, and is most prized by collectors specializing in rare earth and niobium minerals from sites like the Kola Peninsula.
Is this nenadkevichite?
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 nenadkevichite with a known reference. Nenadkevichite sits at Mohs 5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white to very pale rose.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to dull.
- 4Match the color rangeCompare against the expected color range: yellow, brown, rose, tan.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: bladed, prismatic, pseudo hexagonal.
Often confused with
Nenadkevichite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Labuntsovite is the harder of the two (Mohs 6 vs. 5); luster reads vitreous to dull on Nenadkevichite and greasy on Labuntsovite.
How to tell apart: Luster reads vitreous to dull on Nenadkevichite and silky, vitreous to waxy or dull on Elpidite.
Often found alongside nenadkevichite
Minerals reported to co-occur with nenadkevichite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,□)₈Nb₄(Si₄O₁₂)₂(O,OH)₄(H₂O)₈
- Mohs hardness
- 5
- Density
- 2.78-2.885 g/cm³
- Streak
- White to very pale rose
- Luster
- Vitreous to dull
- Transparency
- Opaque to translucent, transparent in very small fragments
- Crystal system
- Orthorhombic
- Crystal habit
- Bladed, prismatic, pseudo hexagonal
- Cleavage
- Poor on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Between crystals of microcline in a natrolite-albite-rich pegmatite in nepheline syenite in a differentiated alkalic massif (Lovozero massif, Russia)
Where rockhounds find nenadkevichite
Classic worldwide localities
- Mts. Karnasurt and Flora, in the Lovozero massif, and in the Vuoriyarvi carbonatite complex, Kola Peninsula, Russia
- Gjerdingen, near Oslo, Norway
- Mont Saint-Hilaire and near Saint-Amable, Quebec, Canada
Field-hunting tip
Where it forms: Between crystals of microcline in a natrolite-albite-rich pegmatite in nepheline syenite in a differentiated alkalic massif (Lovozero massif, Russia). If you start seeing microcline, aegirine, catapleiite in float, you are in the right ground. Typical habit: bladed, prismatic, pseudo hexagonal. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify nenadkevichite?+
Where is nenadkevichite found?+
What rocks look like nenadkevichite?+
What minerals are found with nenadkevichite?+
What kind of rock does nenadkevichite form in?+
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Find nenadkevichite on the map
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