Cordylite-(La) is a rare barium-cerium-lanthanum carbonate mineral typically found in nepheline syenites and associated pegmatites. It forms distinct, clear-to-translucent hexagonal tabular crystals that are highly prized by systematic mineral collectors. It is most famous for its occurrence in the complex alkaline rocks of Mont Saint-Hilaire, Canada.
Is this cordylite-(la)?
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 cordylite-(la) with a known reference. Cordylite-(La) sits at Mohs 4, 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: greasy to vitreous.
- 4Match the color rangeCompare against the expected color range: colorless, honey-yellow, or pinkish yellow.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: tabular crystals, hexagonal prisms.
Often confused with
Cordylite-(La) vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside cordylite-(la)
Minerals reported to co-occur with cordylite-(la). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,Ca)₂Ba₂(La₃Sr)(CO₃)₈F₂
- Mohs hardness
- 4
- Density
- 4.31 g/cm³
- Colors
- Streak
- White
- Luster
- Greasy to vitreous
- Transparency
- Translucent
- Crystal system
- Hexagonal
- Crystal habit
- Tabular crystals, hexagonal prisms
- Cleavage
- Perfect on {0001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In carbonatite lenses associated with a fenite dike
Where rockhounds find cordylite-(la)
Classic worldwide localities
- Biraya Fe-REE deposit, north of the Irkutsk district, 145 km east of Bodaibo city, Russia
Field-hunting tip
Where it forms: In carbonatite lenses associated with a fenite dike. If you start seeing aragonite-strontianite, calcian strontianite, strontian calcite in float, you are in the right ground. Typical habit: tabular crystals, hexagonal prisms. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify cordylite-(la)?+
Where is cordylite-(la) found?+
What rocks look like cordylite-(la)?+
What minerals are found with cordylite-(la)?+
What kind of rock does cordylite-(la) form in?+
What is cordylite-(la) used for?+
Find cordylite-(la) on the map
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