Pitiglianoite is a rare tectosilicate mineral belonging to the cancrinite group, first discovered in the volcanic ejecta of the Pitigliano area in Tuscany. It typically appears as tiny, colorless to white transparent crystals or granular aggregates within vugs of volcanic rocks. Collectors prize it for its rarity and its association with unique alkaline volcanic mineral assemblages.
Is this pitiglianoite?
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 pitiglianoite with a known reference. Pitiglianoite sits at Mohs ~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: colorless.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: prismatic.
Often confused with
Pitiglianoite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside pitiglianoite
Minerals reported to co-occur with pitiglianoite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₂Na₆(Si₆Al₆)O₂₄(SO₄)(H₂O)₂
- Mohs hardness
- ~5
- Density
- 2.37 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Hexagonal
- Crystal habit
- Prismatic
- Cleavage
- Indistinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In metasomatized blocks of volcanic ejecta
Where rockhounds find pitiglianoite
Classic worldwide localities
- Case Collina, Pitigliano, near Grosseto, Tuscany, Italy
Field-hunting tip
Where it forms: In metasomatized blocks of volcanic ejecta. If you start seeing apatite, diopside, grossular in float, you are in the right ground. Typical habit: prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify pitiglianoite?+
Where is pitiglianoite found?+
What rocks look like pitiglianoite?+
What minerals are found with pitiglianoite?+
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What is pitiglianoite used for?+
Find pitiglianoite on the map
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