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, so 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, 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.