Boothite is a rare copper sulfate mineral that typically forms as bright blue, fragile crusts or fibrous efflorescences in mine workings. It is highly unstable in dry air, as it easily loses water to convert into other copper sulfate phases, making well-preserved specimens highly prized by mineral collectors.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareMelanterite Group family

Boothite

Hardness: 2
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this boothite?

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 boothite with a known reference. Boothite 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. Boothite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Boothite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: blue.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: fibrous, acicular, or efflorescent crusts.

Often confused with

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

Often found alongside boothite

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

All properties

Chemical formula: CuSO₄·7H₂O
Mohs hardness: 2
Density: 1.95 g/cm³
Colors: Blue
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Fibrous, Acicular, Or Efflorescent Crusts
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Copper-bearing Ore Deposits
Typical price: $20-100 per specimen

Where rockhounds find boothite

Classic worldwide localities

California, USA
Rio Tinto, Spain
Cyprus

Field-hunting tip

Look in oxidized zones of copper-bearing ore deposits country — that is the host setting where boothite typically forms. If you start seeing chalcanthite, melanterite, gypsum in float, you are in the right ground. Field specimens usually show a fibrous, acicular, or efflorescent crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify boothite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is white. Common colors include blue.

Where is boothite found?+

Notable localities include California, USA; Rio Tinto, Spain; Cyprus.

How much is boothite worth?+

Typical asking prices fall in the range of $20-100 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is boothite safe to handle?+

It contains toxic constituents. Contains copper; handle with care and wash hands thoroughly after handling. Should be kept in a sealed container as it is prone to dehydration. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like boothite?+

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

What minerals are found with boothite?+

Boothite commonly co-occurs with Chalcanthite, Melanterite, Gypsum. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does boothite form in?+

Boothite typically forms in oxidized zones of copper-bearing ore deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is boothite used for?+

Boothite is used in collector.

Find boothite on the map

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