Camanchacaite is a rare sodium calcium magnesium arsenate, typically colorless. It was approved as a distinct mineral species in 2018. It was first described from the Torrecillas mine, Iquique Province, Tarapacá Region, Chile.

Hardness

2.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent to translucent

mineralrareTschermakite family

Camanchacaite

Hardness: 2.5
Luster: Vitreous
Streak: White
Transparency: Transparent to translucent

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Is this camanchacaite?

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 camanchacaite with a known reference. Camanchacaite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: colorless, pink-beige.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals.

Often confused with

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

mineral

Hornblende

Mohs 5-6

How to tell apart: Hornblende is the harder of the two (Mohs 5-6 vs. 2.5); streak differs, so Camanchacaite leaves white, Hornblende leaves grayish-white.

How to tell apart: Tschermakite is the harder of the two (Mohs 5-6 vs. 2.5); streak differs, so Camanchacaite leaves white, Tschermakite leaves greenish white.

How to tell apart: Actinolite is the harder of the two (Mohs 5-6 vs. 2.5).

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Often found alongside camanchacaite

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

All properties

Chemical formula: Na☐CaMg₂(AsO₄)₂[AsO₂(OH)₂]
Mohs hardness: 2.5
Density: 3.568 g/cm³
Colors: ColorlessPink-beige
Streak: White
Luster: Vitreous
Transparency: Transparent to translucent
Crystal system: Monoclinic
Crystal habit: Prismatic crystals
Cleavage: Perfect on {101} and {010} by analogy with other alluaudite-group minerals
Rarity: Rare
Uses: Collector, Research
Host rock: metamorphic rocks

Where rockhounds find camanchacaite

Classic worldwide localities

Torrecillas mine, northern Atacama Desert, Salar Grande, Iquique Province, Tarapacá Region, Chile

Field-hunting tip

Where it forms: metamorphic rocks. If you start seeing magnesiofluckite, picaite, ríosecoite in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify camanchacaite?+

Mohs hardness is 2.5. Luster: vitreous. The streak is white. Common colors include colorless, pink-beige.

Where is camanchacaite found?+

Notable localities include Torrecillas mine, northern Atacama Desert, Salar Grande, Iquique Province, Tarapacá Region, Chile.

Is camanchacaite safe to handle?+

Camanchacaite contains arsenic and calls for real care. Contains arsenic, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust.

What rocks look like camanchacaite?+

Camanchacaite is most often confused with Hornblende, Tschermakite, Actinolite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with camanchacaite?+

Camanchacaite commonly co-occurs with Magnesiofluckite, Picaite, Ríosecoite, Chinchorroite, Currierite, Anhydrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does camanchacaite form in?+

Where it forms: metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is camanchacaite used for?+

Camanchacaite is used in collector, research.

Find camanchacaite on the map

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