Perrierite-(Ce) is a rare rare-earth-bearing silicate that often occurs as tabular to prismatic crystals in alkaline volcanic rocks. It is visually very similar to chevkinite-(Ce) and is typically identified through analytical methods like X-ray diffraction or chemical testing. Collectors primarily find it in specific geological occurrences where rare-earth minerals are concentrated.
Is this perrierite-(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 perrierite-(ce) with a known reference. Perrierite-(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: brown.
- 3Read the lusterHold the specimen under a strong light. Luster: resinous, lustrous to dull.
- 4Match the color rangeCompare against the expected color range: black, brownish, dark reddish brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: massive, metamict, prismatic.
Often confused with
Perrierite-(Ce) vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Perrierite-(Ce) leaves brown, Allanite leaves gray; luster reads resinous, lustrous to dull on Perrierite-(Ce) and submetallic on Allanite.
How to tell apart: Streak differs, so Perrierite-(Ce) leaves brown, Chevkinite-(Ce) leaves black.
Often found alongside perrierite-(ce)
Minerals reported to co-occur with perrierite-(ce). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ce₄MgFe₂Ti₂O₈(Si₂O₇)₂
- Mohs hardness
- 5.5
- Density
- 4.29-4.45 g/cm³
- Streak
- Brown
- Luster
- Resinous, lustrous to dull
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Massive, metamict, prismatic
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In sands derived from weathered tuffs (Nettuno, Italy); in pockets in hypersthene granodiorite (Burley Farm, Virginia, USA); in syenite pegmatites (Oslo, Norway)
Where rockhounds find perrierite-(ce)
Classic worldwide localities
- Burley Farm and at Wares Gap, Amherst Co., north of Chamblissburg, Bedford Co., and on Hat Creek and east of Roseland, Nelson Co., Virginia, USA
- Chimney Rock, Morrill Co., Nebraska, USA
- Yucca Mountain, Nye Co., Nevada, USA
- Nettuno, Lazio, and on Mt. Amiata, Tuscany, Italy
- Desmont mine, near Wilberforce, and west of Golden Lake, Ontario, Canada
- Bangalore, Karnataka, and at Kanjamalaiu, near Salem, Tamil Nadu, India
Field-hunting tip
Where it forms: In sands derived from weathered tuffs (Nettuno, Italy); in pockets in hypersthene granodiorite (Burley Farm, Virginia, USA); in syenite pegmatites (Oslo, Norway). If you start seeing microcline, aegirine, loparite in float, you are in the right ground. Typical habit: massive, metamict, prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify perrierite-(ce)?+
Where is perrierite-(ce) found?+
Is perrierite-(ce) safe to handle?+
What rocks look like perrierite-(ce)?+
What minerals are found with perrierite-(ce)?+
What kind of rock does perrierite-(ce) form in?+
What is perrierite-(ce) used for?+
Find perrierite-(ce) on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
