Luetheite is a rare copper-aluminum arsenate mineral typically found as tiny, sky-blue to greenish-blue platy crystals. It is most famous from the Hilltop Mine in Arizona, where it occurs as a secondary mineral in oxidized ore zones. Collectors value it for its vivid color and association with other rare copper secondary species.

Hardness

Mohs

Luster

Pearly

Streak

Pale Blue

Transparency

Translucent

mineralrare

Luetheite

Hardness: 2
Luster: Pearly
Streak: Pale Blue
Transparency: Translucent

Is this luetheite?

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 luetheite with a known reference. Luetheite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Luetheite leaves a pale blue streak.
3
Read the luster
Hold the specimen under a strong light. Luetheite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: blue, greenish-blue.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals, crusts.

Often confused with

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

mineral

Cornwallite

Mohs 3.5

How to tell apart: Cornwallite is the harder of the two (Mohs 3.5 vs. 2); streak differs — Luetheite leaves pale blue, Cornwallite leaves pale green; luster reads pearly on Luetheite and vitreous on Cornwallite.

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Often found alongside luetheite

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

All properties

Chemical formula: Cu₂Al₂(OH)₆(AsO₄)₂·H₂O
Mohs hardness: 2
Density: 3.84 g/cm³
Colors: Blue Greenish-blue
Streak: Pale Blue
Luster: Pearly
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Platy Crystals, Crusts
Cleavage: Perfect On {001}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Copper-arsenic Ore Deposits
Typical price: $50-300 per thumbnail specimen

Where rockhounds find luetheite

Classic worldwide localities

Hilltop Mine, Arizona, USA

Field-hunting tip

Look in oxidized copper-arsenic ore deposits country — that is the host setting where luetheite typically forms. If you start seeing chrysocolla, jarosite, olivenite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify luetheite?+

Mohs hardness is 2. It typically shows a pearly luster. The streak is pale blue. Common colors include blue, greenish-blue.

Where is luetheite found?+

Notable localities include Hilltop Mine, Arizona, USA.

How much is luetheite worth?+

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

Is luetheite safe to handle?+

It contains toxic constituents. Contains arsenic and copper; avoid ingestion, inhalation of dust, or prolonged skin contact. Wash hands thoroughly after handling specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like luetheite?+

Luetheite is most often confused with Cornwallite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with luetheite?+

Luetheite commonly co-occurs with Chrysocolla, Jarosite, Olivenite, Tyrolite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does luetheite form in?+

Luetheite typically forms in oxidized copper-arsenic ore deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is luetheite used for?+

Luetheite is used in collector.

Find luetheite on the map

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