D'Ansite-(Fe) is an exceptionally rare sulfate mineral found exclusively in active volcanic fumarole environments. It typically forms as small, tabular yellow crystals associated with other volcanic sublimates like chlorothionite.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareD'Ansite Group family

D'Ansite-(Fe)

Hardness: 3.5
Luster: Vitreous
Streak: White
Transparency: Transparent

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Is this d'ansite-(fe)?

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 d'ansite-(fe) with a known reference. D'Ansite-(Fe) sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. D'Ansite-(Fe) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. D'Ansite-(Fe) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, yellowish-orange.
5
Look at form & habit
Crystal system: trigonal. Typical habit: tabular crystals.

Often confused with

D'Ansite-(Fe) vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: D'Ansite-(Fe) is noticeably harder (Mohs 3.5 vs. 2.5).

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Often found alongside d'ansite-(fe)

Minerals reported to co-occur with d'ansite-(fe). Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: Na₂₁Fe(SO₄)₁₀Cl₃
Mohs hardness: 3.5
Density: 2.81 g/cm³
Colors: Yellow Yellowish-orange
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Tabular Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Fumarole Deposits
Typical price: $100-500 for micro-specimens

Where rockhounds find d'ansite-(fe)

Classic worldwide localities

D'Ansite fumarole, La Fossa Crater, Vulcano, Aeolian Islands, Italy

Field-hunting tip

Look in fumarole deposits country — that is the host setting where d'ansite-(fe) typically forms. If you start seeing chlorothionite, euchlorine, thenardite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify d'ansite-(fe)?+

Mohs hardness is 3.5. It typically shows a vitreous luster. The streak is white. Common colors include yellow, yellowish-orange.

Where is d'ansite-(fe) found?+

Notable localities include D'Ansite fumarole, La Fossa Crater, Vulcano, Aeolian Islands, Italy.

How much is d'ansite-(fe) worth?+

Typical asking prices fall in the range of $100-500 for micro-specimens. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like d'ansite-(fe)?+

D'Ansite-(Fe) is most often confused with D'Ansite-(Mn), Chlorothionite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with d'ansite-(fe)?+

D'Ansite-(Fe) commonly co-occurs with Chlorothionite, Euchlorine, Thenardite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does d'ansite-(fe) form in?+

D'Ansite-(Fe) typically forms in fumarole deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is d'ansite-(fe) used for?+

D'Ansite-(Fe) is used in collector.

Find d'ansite-(fe) on the map

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