Brüggenite is a rare calcium iodate mineral found exclusively in the hyper-arid nitrate deposits of the Atacama Desert. Collectors prize it for its sharp, transparent monoclinic crystals that are often found associated with other rare iodine-bearing species like dietzeite.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Brüggenite

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

Is this brüggenite?

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 brüggenite with a known reference. Brüggenite 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. Brüggenite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Brüggenite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals, subparallel aggregates.

Often confused with

Brüggenite 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 — Brüggenite leaves white, Dietzeite leaves yellow.

Often found alongside brüggenite

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

All properties

Chemical formula: Ca(IO₃)₂(HIO₃)₂
Mohs hardness: 3.5
Density: 2.84 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals, Subparallel Aggregates
Cleavage: Perfect On {010}
Rarity: Rare
Uses: Collector, Scientific Research
Host rock: Nitrate-rich Evaporite Deposits
Typical price: $50-300+ for micro-specimens

Where rockhounds find brüggenite

Classic worldwide localities

Atacama Desert, Chile

Field-hunting tip

Look in nitrate-rich evaporite deposits country — that is the host setting where brüggenite typically forms. If you start seeing dietzeite, lautarite, gypsum in float, you are in the right ground. Field specimens usually show a tabular crystals, subparallel aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify brüggenite?+

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

Where is brüggenite found?+

Notable localities include Atacama Desert, Chile.

How much is brüggenite worth?+

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

What rocks look like brüggenite?+

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

What minerals are found with brüggenite?+

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

What kind of rock does brüggenite form in?+

Brüggenite typically forms in nitrate-rich evaporite deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is brüggenite used for?+

Brüggenite is used in collector, scientific research.

Find brüggenite on the map

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