Lautarite is a rare calcium iodate mineral found primarily in the nitrate deposits of the Atacama Desert. It typically forms colorless to yellowish prismatic crystals that are highly soluble in water, making it a challenging mineral to collect and store in humid environments.

Hardness

3-3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Lautarite

Hardness: 3-3.5
Luster: Vitreous
Streak: White
Transparency: Transparent

No image

Is this lautarite?

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 lautarite with a known reference. Lautarite sits at Mohs 3-3.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Lautarite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Lautarite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white, yellowish.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals, massive, granular.

Often confused with

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

mineral

Dietzeite

Mohs 3-3.5

How to tell apart: Streak differs — Lautarite leaves white, Dietzeite leaves yellow.

How to tell apart: Lautarite is noticeably harder (Mohs 3-3.5 vs. 2).

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Often found alongside lautarite

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

All properties

Chemical formula: Ca(IO₃)₂
Mohs hardness: 3-3.5
Density: 4.59 g/cm³
Colors: Colorless White Yellowish
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Prismatic Crystals, Massive, Granular
Cleavage: Distinct On {110}
Rarity: Rare
Uses: Collector
Host rock: Nitrate-bearing Deposits in Arid Desert Regions
Typical price: $50-500 depending on specimen size and clarity

Where rockhounds find lautarite

Classic worldwide localities

Atacama Desert, Chile

Field-hunting tip

Look in nitrate-bearing deposits in arid desert regions country — that is the host setting where lautarite typically forms. If you start seeing dietzeite, halite, gypsum in float, you are in the right ground. Field specimens usually show a prismatic crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify lautarite?+

Mohs hardness is 3-3.5. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, yellowish.

Where is lautarite found?+

Notable localities include Atacama Desert, Chile.

How much is lautarite worth?+

Typical asking prices fall in the range of $50-500 depending on specimen size and clarity. Quality, size, and provenance can move individual specimens well outside that range.

Is lautarite safe to handle?+

It contains toxic constituents. Contains iodine and is potentially toxic if ingested or inhaled as dust; wash hands thoroughly after handling specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like lautarite?+

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

What minerals are found with lautarite?+

Lautarite commonly co-occurs with Dietzeite, Halite, Gypsum, Darapskite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does lautarite form in?+

Lautarite typically forms in nitrate-bearing deposits in arid desert regions. Working float back to the host body is the standard way to chase a fresh occurrence.

What is lautarite used for?+

Lautarite is used in collector.

Find lautarite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.