Cesanite is a rare sodium-calcium sulfate mineral that was first discovered in volcanic deposits near Cesan, Italy. It typically forms as small, colorless to white prismatic crystals and is prized by mineralogists for its rarity and structural relationship to the apatite group.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareApatite Group family

Cesanite

Hardness: 5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this cesanite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch cesanite with a known reference. Cesanite sits at Mohs 5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Cesanite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Cesanite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: white, colorless.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: prismatic crystals.

Often confused with

Cesanite vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Cesanite is noticeably harder (Mohs 5 vs. 3.5).

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Often found alongside cesanite

Minerals reported to co-occur with cesanite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: Na₈Ca₂(SO₄)₆(OH)₂
Mohs hardness: 5
Density: 2.79 g/cm³
Colors: White Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Hexagonal
Crystal habit: Prismatic Crystals
Cleavage: Indistinct
Rarity: Rare
Uses: Collector
Host rock: Volcanic Ejecta
Typical price: $50-300 per specimen

Where rockhounds find cesanite

Classic worldwide localities

Cesan, Latium, Italy

Field-hunting tip

Look in volcanic ejecta country — that is the host setting where cesanite typically forms. If you start seeing calcite, gypsum, sulfur 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

How do you identify cesanite?+

Mohs hardness is 5. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless.

Where is cesanite found?+

Notable localities include Cesan, Latium, Italy.

How much is cesanite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like cesanite?+

Cesanite is most often confused with Apatite, Anhydrite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with cesanite?+

Cesanite commonly co-occurs with Calcite, Gypsum, Sulfur. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does cesanite form in?+

Cesanite typically forms in volcanic ejecta. Working float back to the host body is the standard way to chase a fresh occurrence.

What is cesanite used for?+

Cesanite is used in collector.

Find cesanite on the map

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