Connellite is a rare, striking copper sulfate chloride mineral that typically forms as delicate, needle-like blue sprays or tufts. It is most famous from the mines of Cornwall, England, where it occurs as a secondary mineral in oxidized copper-rich environments. Collectors value it for its vivid blue color and complex, acicular crystalline habit.

Hardness

Mohs

Luster

Vitreous

Streak

Pale Blue

Transparency

Translucent

mineralrare

Connellite

Hardness: 3
Luster: Vitreous
Streak: Pale Blue
Transparency: Translucent

Is this connellite?

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 connellite with a known reference. Connellite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Connellite leaves a pale blue streak.
3
Read the luster
Hold the specimen under a strong light. Connellite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: bright blue, azure blue, deep blue.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: acicular or fibrous radial sprays, prismatic crystals.

Often confused with

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

mineral

Azurite

Mohs 3.5-4

How to tell apart: Streak differs, so Connellite leaves pale blue, Azurite leaves light blue; luster reads vitreous on Connellite and vitreous to dull on Azurite.

Often found alongside connellite

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

All properties

Chemical formula: Cu₁₉(SO₄)(OH)₃₂Cl₄·3H₂O
Mohs hardness: 3
Density: 3.4-3.5 g/cm³
Colors: Bright Blue Azure Blue Deep Blue
Streak: Pale Blue
Luster: Vitreous
Transparency: Translucent
Crystal system: Hexagonal
Crystal habit: Acicular or Fibrous Radial Sprays, Prismatic Crystals
Cleavage: Good On {10-10}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Copper Ore Deposits
Typical price: $20-150 thumbnail, $200+ cabinet specimen

Where rockhounds find connellite

Classic worldwide localities

Cornwall, England
Bisbee, Arizona, USA
Tsumeb, Namibia
Chuquicamata, Chile

Field-hunting tip

Look in oxidized copper ore deposits country, the host setting where connellite typically forms. If you start seeing cuprite, malachite, brochantite in float, you are in the right ground. Field specimens usually show a acicular or fibrous radial sprays, prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify connellite?+

Mohs hardness is 3. It typically shows a vitreous luster. The streak is pale blue. Common colors include bright blue, azure blue, deep blue.

Where is connellite found?+

Notable localities include Cornwall, England; Bisbee, Arizona, USA; Tsumeb, Namibia; Chuquicamata, Chile.

How much is connellite worth?+

Typical asking prices fall in the range of $20-150 thumbnail, $200+ cabinet specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is connellite safe to handle?+

It contains toxic constituents. Contains copper; avoid ingesting dust or skin contact during handling. Wash hands thoroughly after processing samples. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like connellite?+

Connellite is most often confused with Azurite, Linarite, Devilline. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with connellite?+

Connellite commonly co-occurs with Cuprite, Malachite, Brochantite, Azurite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does connellite form in?+

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

What is connellite used for?+

Connellite is used in collector.

Find connellite on the map

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