Joteite is a very rare copper-calcium arsenate mineral known primarily from the Jote mine in Chile. It typically forms as delicate, tabular sky-blue to greenish blue crystals within oxidized zones of arsenic-rich copper deposits.

Hardness

2-3

Mohs

Luster

Vitreous

Streak

Very pale blue

Transparency

Transparent

mineralrare

Joteite

Hardness: 2-3
Luster: Vitreous
Streak: Very pale blue
Transparency: Transparent

Is this joteite?

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 joteite with a known reference. Joteite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: very pale blue.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: sky-blue, greenish blue.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular crystals.

Often confused with

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

mineral

Conichalcite

Mohs 4.5

How to tell apart: Conichalcite is the harder of the two (Mohs 4.5 vs. 2-3); streak differs, so Joteite leaves very pale blue, Conichalcite leaves green.

How to tell apart: Austinite is the harder of the two (Mohs 4-4.5 vs. 2-3); streak differs, so Joteite leaves very pale blue, Austinite leaves white; luster reads vitreous on Joteite and subadamantine to silky in aggregates on Austinite.

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Often found alongside joteite

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

All properties

Chemical formula: Ca₂CuAl(AsO₄)[AsO₃(OH)]₂(OH)₂·5H₂O
Mohs hardness: 2-3
Density: 3.084 g/cm³
Colors: Sky-blue Greenish blue
Streak: Very pale blue
Luster: Vitreous
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Tabular crystals
Cleavage: Perfect on {001}
Rarity: Rare
Uses: Collector
Host rock: In narrow seams and vugs in the oxidized upper portion of a hydrothermal sulfide vein hosted by volcanoclastic rocks

Where rockhounds find joteite

Classic worldwide localities

Jote mine, Pampa Larga district, Tierra Amarilla, Copiapó Province, Atacama, Chile

Field-hunting tip

Where it forms: In narrow seams and vugs in the oxidized upper portion of a hydrothermal sulfide vein hosted by volcanoclastic rocks. If you start seeing conichalcite, mansfieldite, pharmacoalumite in float, you are in the right ground. Typical habit: tabular crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify joteite?+

Mohs hardness is 2-3. Luster: vitreous. The streak is very pale blue. Common colors include sky-blue, greenish blue.

Where is joteite found?+

Notable localities include Jote mine, Pampa Larga district, Tierra Amarilla, Copiapó Province, Atacama, Chile.

Is joteite safe to handle?+

Joteite contains arsenic and copper and calls for real care. Contains arsenic, which is toxic; wash hands thoroughly after handling and avoid inhaling dust.

What rocks look like joteite?+

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

What minerals are found with joteite?+

Joteite commonly co-occurs with Conichalcite, Mansfieldite, Pharmacoalumite, Pharmacosiderite, Scorodite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does joteite form in?+

Where it forms: In narrow seams and vugs in the oxidized upper portion of a hydrothermal sulfide vein hosted by volcanoclastic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is joteite used for?+

Joteite is used in collector.

Find joteite on the map

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