Gottardiite is a rare member of the zeolite group often found in volcanic cavities within basalt. It forms clear to white tabular crystals that strongly resemble stilbite, and identification usually requires X-ray diffraction due to its structural complexity.
Is this gottardiite?
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 gottardiite with a known reference. Gottardiite sits at Mohs 4, 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: colorless.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular crystals, aggregates.
Often confused with
Gottardiite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside gottardiite
Minerals reported to co-occur with gottardiite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₃Mg₃Ca₅Al₁₉Si₁₁₇O₂₇₂·93H₂O
- Mohs hardness
- 4
- Density
- 2.14 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular crystals, aggregates
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- basaltic cavities
Where rockhounds find gottardiite
Classic worldwide localities
- Mt. Adamson, Victoria Land, Antarctica (type locality)
Field-hunting tip
Where it forms: basaltic cavities. If you start seeing calcite, quartz, heulandite in float, you are in the right ground. Typical habit: tabular crystals, aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify gottardiite?+
Where is gottardiite found?+
What rocks look like gottardiite?+
What minerals are found with gottardiite?+
What kind of rock does gottardiite form in?+
What is gottardiite used for?+
Find gottardiite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
