Sputnik Aragonite is a popular collector's specimen characterized by its distinctive star-shaped or cross-shaped cyclic twinning patterns. These clusters form in sedimentary environments, most famously in the clay beds of Spain, often displaying a soft brown or tan hue with a sharp, geometric aesthetic.
Is this sputnik aragonite?
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 sputnik aragonite with a known reference. Sputnik Aragonite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Sputnik Aragonite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Sputnik Aragonite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: brown, tan, creamy white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: star-shaped cyclic twin clusters.
Often confused with
Sputnik Aragonite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside sputnik aragonite
Minerals reported to co-occur with sputnik aragonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaCO₃
- Mohs hardness
- 3.5-4
- Density
- 2.95 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Star-shaped Cyclic Twin Clusters
- Cleavage
- Distinct On {010}
- Fluorescence
- Often Bright Yellow or Cream Under SW UV
- Rarity
- Common
- Uses
- Collector, Decorative
- Host rock
- Sedimentary Deposits in Clay or Gypsum Beds
- Typical price
- $5-50 for typical clusters
Where rockhounds find sputnik aragonite
Classic worldwide localities
- Minglanilla, Spain
- Taze, Morocco
- Dzierżno, Poland
Field-hunting tip
Look in sedimentary deposits in clay or gypsum beds country — that is the host setting where sputnik aragonite typically forms. If you start seeing gypsum, calcite, sulfur in float, you are in the right ground. Field specimens usually show a star-shaped cyclic twin clusters habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify sputnik aragonite?+
Where is sputnik aragonite found?+
How much is sputnik aragonite worth?+
What rocks look like sputnik aragonite?+
What minerals are found with sputnik aragonite?+
What kind of rock does sputnik aragonite form in?+
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Find sputnik aragonite on the map
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