Middlebackite is a rare lead-copper carbonate chloride mineral discovered in the oxidized zones of ore deposits in South Australia. It is typically found as small, distinct blue tabular crystals and is highly sought after by advanced collectors for its rarity and crystal form.

Hardness
2-3
Mohs
Luster
Vitreous
Streak
Pale Blue
Transparency
Transparent

Is this middlebackite?

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 middlebackite with a known reference. Middlebackite 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. Middlebackite leaves a pale blue streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Middlebackite 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: tabular crystals.

Often confused with

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

Often found alongside middlebackite

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

All properties

Chemical formula
Pb₂Cu(CO₃)(OH)₂Cl₂
Mohs hardness
2-3
Density
3.51 g/cm³
Colors
Streak
Pale Blue
Luster
Vitreous
Transparency
Transparent
Crystal system
Monoclinic
Crystal habit
Tabular Crystals
Cleavage
Perfect
Rarity
Rare
Uses
Collector
Host rock
Oxidized Zones of Lead-copper Ore Deposits
Typical price
$100-500 thumbnail, $500+ cabinet

Where rockhounds find middlebackite

Classic worldwide localities

  • Middleback Range, South Australia

Field-hunting tip

Look in oxidized zones of lead-copper ore deposits country — that is the host setting where middlebackite typically forms. If you start seeing cerussite, malachite, goethite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify middlebackite?+
Mohs hardness is 2-3. It typically shows a vitreous luster. The streak is pale blue. Common colors include blue.
Where is middlebackite found?+
Notable localities include Middleback Range, South Australia.
How much is middlebackite worth?+
Typical asking prices fall in the range of $100-500 thumbnail, $500+ cabinet. Quality, size, and provenance can move individual specimens well outside that range.
Is middlebackite safe to handle?+
It contains toxic constituents. Contains lead and copper, which are toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust when breaking specimens. Handle with care, avoid grinding or breathing dust, and store separately.
What rocks look like middlebackite?+
Middlebackite is most often confused with Cerussite, Malachite, Phosgenite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with middlebackite?+
Middlebackite commonly co-occurs with Cerussite, Malachite, Goethite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does middlebackite form in?+
Middlebackite typically forms in oxidized zones of lead-copper ore deposits. Working float back to the host body is the standard way to chase a fresh occurrence.
What is middlebackite used for?+
Middlebackite is used in collector.

Find middlebackite on the map

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