Joaquinite-(Ce) is a rare silicate mineral primarily known from the world-famous Benitoite Gem Mine in California. It typically forms attractive, honey-colored wedge-shaped crystals perched on white natrolite or associated with deep red neptunite, making it a highly prized specimen for collectors of rare earth minerals.
Is this joaquinite-(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 joaquinite-(ce) with a known reference. Joaquinite-(Ce) sits at Mohs 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: honey yellow, brown, orange.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: euhedral crystals.
Often confused with
Joaquinite-(Ce) vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside joaquinite-(ce)
Minerals reported to co-occur with joaquinite-(ce). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaBa₂Fe²⁺Ce₂Ti₂Si₈O₂₆(OH)·H₂O
- Mohs hardness
- 5.5
- Density
- 3.89-3.98 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Euhedral crystals
- Cleavage
- {001}, good
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a natrolite vein cutting a glaucophane schist inclusion in a serpentinite body (San Benito Co., California, USA); in fenitized gneisses and alkalic syenites (Seal Lake, Canada)
Where rockhounds find joaquinite-(ce)
Classic worldwide localities
- Gem mine and to its north, on Santa Rita peak, USA
- Mina Numero Uno and on the Victor claim, San Benito Co., California, USA
- Granite Mountain, near Little Rock, Pulaski Co., Arkansas, USA
- Seal Lake, Labrador, Newfoundland, and Mont Saint-Hilaire, Quebec, Canada
Field-hunting tip
Where it forms: In a natrolite vein cutting a glaucophane schist inclusion in a serpentinite body (San Benito Co., California, USA); in fenitized gneisses and alkalic syenites (Seal Lake, Canada). If you start seeing orthojoaquinite-, benitoite, neptunite in float, you are in the right ground. Typical habit: euhedral crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify joaquinite-(ce)?+
Where is joaquinite-(ce) found?+
What rocks look like joaquinite-(ce)?+
What minerals are found with joaquinite-(ce)?+
What kind of rock does joaquinite-(ce) form in?+
What is joaquinite-(ce) used for?+
Find joaquinite-(ce) on the map
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