Aeschynite-(Ce) is a rare-earth-bearing complex oxide typically found as dark, tabular crystals in pegmatite bodies. Collectors should look for its distinct resinous luster and often heavily striated crystal faces. It is significantly radioactive, requiring careful handling and storage techniques for the long-term protection of the collector and other minerals.
Is this aeschynite-(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 aeschynite-(ce) with a known reference. Aeschynite-(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. Streak: nearly black to brown.
- 3Read the lusterHold the specimen under a strong light. Luster: submetallic, resinous to waxy; dull when altered.
- 4Match the color rangeCompare against the expected color range: black, brown, brownish black, yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: acicular, massive.
Often confused with
Aeschynite-(Ce) vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Aeschynite-(Ce) leaves nearly black to brown, Euxenite-(Y) leaves yellowish, grayish, or reddish brown; luster reads submetallic, resinous to waxy; dull when altered on Aeschynite-(Ce) and brilliant submetallic, waxy to resinous on fractures on Euxenite-(Y).
How to tell apart: Streak differs, so Aeschynite-(Ce) leaves nearly black to brown, Columbite leaves blackish brown.
Often found alongside aeschynite-(ce)
Minerals reported to co-occur with aeschynite-(ce). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ce(TiNb)O₆
- Mohs hardness
- 5-6
- Density
- 5.19 g/cm³
- Streak
- Nearly black to brown
- Luster
- Submetallic, resinous to waxy; dull when altered
- Transparency
- Translucent, transparent in very thin fragments
- Crystal system
- Orthorhombic
- Crystal habit
- Acicular, massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Source of rare earth elements
- Host rock
- In nepheline syenites and alkali syenite massifs; in granite pegmatites; in carbonatites in alkalic rocks; a detrital mineral in placers
Where rockhounds find aeschynite-(ce)
Classic worldwide localities
- South of Darby, Ravalli Co., Montana, and in the Henderson molybdenum mine, Clear Creek Co., Colorado, USA
- Miass and Zlatoust, Vishnevy-Ilmen Mountains, Southern Ural Mountains, Russia
- Hidra (Hitterö) Island, from near Arendal, at Frikstad, Norway
- Döbschütz and Königshaln, Lausiter Bergland, Germany
- Leckbachscharte, Habachtal, and in the Lohninger quarry, near Rauris, Austria
- Val Bedretto and Val Nalps, Tavetsch, Graubünden, Switzerland
Field-hunting tip
Where it forms: In nepheline syenites and alkali syenite massifs; in granite pegmatites; in carbonatites in alkalic rocks; a detrital mineral in placers. If you start seeing feldspar, zircon, samarskite in float, you are in the right ground. Typical habit: acicular, massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify aeschynite-(ce)?+
Where is aeschynite-(ce) found?+
Is aeschynite-(ce) safe to handle?+
What rocks look like aeschynite-(ce)?+
What minerals are found with aeschynite-(ce)?+
What kind of rock does aeschynite-(ce) form in?+
What is aeschynite-(ce) used for?+
Find aeschynite-(ce) on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
