Polyakovite-(Ce) is a rare member of the perrierite group found primarily in alkaline pegmatites. It is typically identified as small, dark, submetallic tabular crystals that are often radioactive due to their thorium content.
Is this polyakovite-(ce)?
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 polyakovite-(ce) with a known reference. Polyakovite-(Ce) 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. Polyakovite-(Ce) leaves a brown streak.
- 3Read the lusterHold the specimen under a strong light. Polyakovite-(Ce) typically shows a submetallic luster.
- 4Match the color rangeCompare against the expected color range: black, brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals.
Often confused with
Polyakovite-(Ce) vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Polyakovite-(Ce) leaves brown, Allanite leaves gray.
How to tell apart: Streak differs — Polyakovite-(Ce) leaves brown, Perrierite-(Ce) leaves light brown; luster reads submetallic on Polyakovite-(Ce) and resinous on Perrierite-(Ce).
Often found alongside polyakovite-(ce)
Minerals reported to co-occur with polyakovite-(ce). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Ce,Ca,Th,Na)₄(Mg,Fe²⁺)₂(Ti,Fe³⁺,Al,Cr)₃Si₄O₂₂
- Mohs hardness
- 5-6
- Density
- 4.8-4.9 g/cm³
- Streak
- Brown
- Luster
- Submetallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alkaline Pegmatites
- Typical price
- $100-500 depending on specimen quality
Where rockhounds find polyakovite-(ce)
Classic worldwide localities
- Ilmen Mountains, Russia
- Kola Peninsula, Russia
Field-hunting tip
Look in alkaline pegmatites country — that is the host setting where polyakovite-(ce) typically forms. If you start seeing zircon, apatite, feldspar in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify polyakovite-(ce)?+
Where is polyakovite-(ce) found?+
How much is polyakovite-(ce) worth?+
Is polyakovite-(ce) safe to handle?+
What rocks look like polyakovite-(ce)?+
What minerals are found with polyakovite-(ce)?+
What kind of rock does polyakovite-(ce) form in?+
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Find polyakovite-(ce) on the map
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