Celestite concretions form as rounded nodules or geodic bodies within sedimentary sequences, often containing hollow centers lined with delicate, pale blue prismatic crystals. Collectors look for these in sedimentary limestone layers where the exterior appears as a dull, unremarkable rock that hides a cavity filled with radiant blue mineral blades.
Is this celestite concretions?
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 celestite concretions with a known reference. Celestite Concretions sits at Mohs 3-3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Celestite Concretions leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Celestite Concretions typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: blue, white, colorless, pale yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular crystals within spherical or irregular sedimentary concretions.
Often confused with
Celestite Concretions vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside celestite concretions
Minerals reported to co-occur with celestite concretions. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SrSO₄
- Mohs hardness
- 3-3.5
- Density
- 3.9-4.0 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular Crystals Within Spherical or Irregular Sedimentary Concretions
- Cleavage
- Perfect Basal
- Rarity
- Common
- Uses
- Collector, Decorative
- Host rock
- Sedimentary Limestone or Shale
- Typical price
- $10-150 depending on size and crystal quality
Where rockhounds find celestite concretions
1 mapped spotsClassic worldwide localities
- Lake Erie (Ohio, USA)
- Madagascar
- Poland
- Tunisia
Field-hunting tip
Look in sedimentary limestone or shale country — that is the host setting where celestite concretions typically forms. If you start seeing calcite, dolomite, gypsum in float, you are in the right ground. Field specimens usually show a tabular crystals within spherical or irregular sedimentary concretions habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in California — start trip planning there.
Common questions
How do you identify celestite concretions?+
Where is celestite concretions found?+
Can I find celestite concretions in the United States?+
How much is celestite concretions worth?+
What rocks look like celestite concretions?+
What minerals are found with celestite concretions?+
What kind of rock does celestite concretions form in?+
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Find celestite concretions on the map
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