Sacrofanite is a rare member of the cancrinite group, occurring primarily in volcanic ejecta found within the Roman volcanic province. It typically forms small, prismatic crystals with a vitreous luster, often found associated with minerals like calcite and sanidine in cavity linings. Because it is highly specific to a single geologic province, specimens are highly sought after by systematic mineral collectors.
Is this sacrofanite?
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 sacrofanite with a known reference. Sacrofanite sits at Mohs 5-6 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Sacrofanite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Sacrofanite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, yellow, colorless.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: prismatic crystals.
Often confused with
Sacrofanite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside sacrofanite
Minerals reported to co-occur with sacrofanite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,Ca,K)₁₅(Si,Al)₂₄O₄₈(SO₄,CO₃,Cl,OH)₃·nH₂O
- Mohs hardness
- 5-6
- Density
- 2.35-2.40 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Hexagonal
- Crystal habit
- Prismatic Crystals
- Cleavage
- Distinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Volcanic Ejecta and Tuffs
- Typical price
- $50-300 per specimen
Where rockhounds find sacrofanite
Classic worldwide localities
- Sacrofano, Italy
- Vico Volcano, Italy
Field-hunting tip
Look in volcanic ejecta and tuffs country — that is the host setting where sacrofanite typically forms. If you start seeing calcite, sanidine, fluorite in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find sacrofanite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
