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, 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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