Calcioancylite-(Ce) is a rare secondary carbonate mineral often found as small, sharp, pseudo-octahedral crystals. It is primarily identified in alkaline igneous environments, especially famous in the nepheline syenites of Mont Saint-Hilaire. Collectors prize it for its distinct, geometric habit and its occurrence in complex mineral assemblages associated with rare-earth element deposits.
Is this calcioancylite-(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 calcioancylite-(ce) with a known reference. Calcioancylite-(Ce) sits at Mohs 4-4.5, 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, greasy on fractures.
- 4Match the color rangeCompare against the expected color range: colorless, gray, pale yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: pseudo octohedral.
Often confused with
Calcioancylite-(Ce) vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside calcioancylite-(ce)
Minerals reported to co-occur with calcioancylite-(ce). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Ce,Ca,Sr)(CO₃)(OH,H₂O)
- Mohs hardness
- 4-4.5
- Density
- 3.95 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous, greasy on fractures
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Pseudo octohedral
- Cleavage
- None
- Fluorescence
- Blue gray under SW and LW UV
- Rarity
- Rare
- Uses
- Collector, Scientific study
- Host rock
- alkaline igneous rocks, pegmatites, carbonatites
Where rockhounds find calcioancylite-(ce)
Classic worldwide localities
- Keystone quarry, near Cornog, Chester Co., Pennsylvania, and at the Foote mine, Cleveland Co., North Carolina, USA
- Originally found in a glacial erratic boulder, Russia
- Afrikanda pyroxenite massif, Kola Peninsula, and at Dodo and Puiva, Polar Ural Mountains, Russia
- Baveno, Italy
- Kalcherkogel tunnel, Styria, Austria
- Found near Mendig, Eifel, Germany
Field-hunting tip
Where it forms: alkaline igneous rocks, pegmatites, carbonatites. If you start seeing potassic feldspar, natrolite, aegirine in float, you are in the right ground. Typical habit: pseudo octohedral. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify calcioancylite-(ce)?+
Where is calcioancylite-(ce) found?+
What rocks look like calcioancylite-(ce)?+
What minerals are found with calcioancylite-(ce)?+
What kind of rock does calcioancylite-(ce) form in?+
What is calcioancylite-(ce) used for?+
Find calcioancylite-(ce) on the map
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