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

mineralrareTschermakite family

Camanchacaite

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

No image

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. Camanchacaite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Camanchacaite typically shows a vitreous luster.
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 pale gray-green.

How to tell apart: Actinolite is the harder of the two (Mohs 5.5-6 vs. 2.5); luster reads vitreous on Camanchacaite and vitreous to silky on Actinolite.

Compare →

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: Colorless Pink-beige
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Prismatic Crystals
Cleavage: Perfect in Two Directions
Rarity: Rare
Uses: Collector, Research
Host rock: Metamorphic Rocks

Where rockhounds find camanchacaite

Classic worldwide localities

Camanchaca, Chile

Field-hunting tip

Look in metamorphic rocks country, the host setting where camanchacaite typically forms. If you start seeing plagioclase, quartz, epidote in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify camanchacaite?+

Mohs hardness is 2.5. It typically shows a vitreous luster. The streak is white. Common colors include colorless, pink-beige.

Where is camanchacaite found?+

Notable localities include Camanchaca, Chile.

Is camanchacaite safe to handle?+

It contains toxic constituents. Contains arsenic, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.

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 Plagioclase, Quartz, Epidote. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does camanchacaite form in?+

Camanchacaite typically forms in 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.