Stellerite is a distinct zeolite mineral that often forms beautiful, fan-shaped or radiating aggregates of tabular crystals. It is frequently found lining cavities in volcanic rocks and is often visually confused with stilbite, though it typically lacks the prominent sheaf-like curvature found in the latter.
Is this stellerite?
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 stellerite with a known reference. Stellerite sits at Mohs 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.
- 4Match the color rangeCompare against the expected color range: white, pink, salmon orange, brown, red.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: spherical, stellate, tabular.
Often confused with
Stellerite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside stellerite
Minerals reported to co-occur with stellerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₄(Al₈Si₂₈O₇₂)·28H₂O
- Mohs hardness
- 4.5
- Density
- 2.13 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Spherical, stellate, tabular
- Cleavage
- {010}, perfect
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- Lines cavities and fracture surfaces in volcanic rocks altered by hydrothermal solutions
Where rockhounds find stellerite
1 mapped spotsClassic worldwide localities
- Ritter Hot Springs, Grant Co., Oregon, USA
- Hook Mountain, Rockland Co., New York, USA
- Fanwood, Somerset Co., New Jersey, USA
- Copper Island, Komandorskiye (Commander) Islands, Bering Sea, and at Klichka, Chita region, Siberia, Russia
- Sarbayskaya quarry, near Rudniy, Kazakhstan
- Villanova Monteleone, Alghero, Sardinia, Italy
Field-hunting tip
Where it forms: Lines cavities and fracture surfaces in volcanic rocks altered by hydrothermal solutions. If you start seeing zeolites, prehnite, tridymite in float, you are in the right ground. Typical habit: spherical, stellate, tabular. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Utah. Start trip planning there.
Common questions
How do you identify stellerite?+
Where is stellerite found?+
Can I find stellerite in the United States?+
What rocks look like stellerite?+
What minerals are found with stellerite?+
What kind of rock does stellerite form in?+
What is stellerite used for?+
Find stellerite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
