Mendeleevite-(Ce) is an extremely rare and complex silicate mineral found in the alkaline pegmatites of the Lovozero Massif. Collectors prize it for its unique composition and association with other rare-earth minerals, though it is usually found as small, dark, radioactive crystal aggregates.
Is this mendeleevite-(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 mendeleevite-(ce) with a known reference. Mendeleevite-(Ce) sits at Mohs 5-5.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: colorless, clear tea color.
- 5Look at form & habitCrystal system: cubic. Typical habit: tabular crystals, aggregates.
Often confused with
Mendeleevite-(Ce) vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside mendeleevite-(ce)
Minerals reported to co-occur with mendeleevite-(ce). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cs₆(Ce,REE,Ca)₃₀(Si₇₀O₁₇₅)(OH,F,H₂O)₃₅
- Mohs hardness
- 5-5.5
- Density
- 3.12 g/cm³
- Colors
- ColorlessClear tea color
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Cubic
- Crystal habit
- Tabular crystals, aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a massif composed of a variety of granitic, alkaline granitic and syenitic pegmatites, various hydrothermal rocks (albitites, fenites) and carbonatites
Where rockhounds find mendeleevite-(ce)
Classic worldwide localities
- Darai-Pioz alkaline massif, Garm District, Tajikistan
Field-hunting tip
Where it forms: In a massif composed of a variety of granitic, alkaline granitic and syenitic pegmatites, various hydrothermal rocks (albitites, fenites) and carbonatites. If you start seeing pectolite, amounts of quartz, aegirine in float, you are in the right ground. Typical habit: tabular crystals, aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify mendeleevite-(ce)?+
Where is mendeleevite-(ce) found?+
Is mendeleevite-(ce) safe to handle?+
What rocks look like mendeleevite-(ce)?+
What minerals are found with mendeleevite-(ce)?+
What kind of rock does mendeleevite-(ce) form in?+
What is mendeleevite-(ce) used for?+
Find mendeleevite-(ce) on the map
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