How to identify Malachite

To correctly identify Malachite (Malachite), check each of these features in order. Many rocks and minerals look alike, so cross-reference multiple properties before deciding.

Step-by-step identification

1. 1

   Color

   Overall color and any zoning or banding

   Vivid green, ranging from light to very dark green, often with characteristic banding in various shades of green.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Adamantine to vitreous on crystals, silky in fibrous aggregates, dull to earthy in massive forms.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Often botryoidal, mammillary, stalactitic, or massive. Fibrous varieties can have a silky texture. Polished surfaces reveal concentric banding.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Monoclinic system, but well-formed crystals are rare. Typically occurs as radiating, fibrous, botryoidal, mammillary, stalactitic, or massive aggregates. Pseudomorphs after azurite are also known.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Perfect on {201}, but rarely observed due to its typical massive or fibrous habit. Fracture is conchoidal to uneven.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Found in the oxidized zones of copper ore deposits, often in association with limestones or dolomites, where copper-rich solutions react with carbonate minerals or carbon dioxide. It is a common alteration product of primary copper sulfides.

Key Facts

Hardness

3.5 - 4 on the Mohs scale

Specific Gravity

3.6 - 4.05

Crystal System

Monoclinic

Color

Bright green to dark green, often banded

Luster

Adamantine to vitreous (on crystals), silky (fibrous), dull to earthy (massive)

Transparency

Translucent to opaque

Fracture

Conchoidal to uneven

Cleavage

Perfect on {201}, but rarely observed

Composition

Copper carbonate hydroxide (Cu₂CO₃(OH)₂)

Physical characteristics

• Crystal Habit: Typically botryoidal, mammillary, stalactitic, massive, fibrous, or earthy. Rarely as acicular or tabular crystals.
• Cleavage Type: Perfect on {201}, but usually not visible due to common habits.
• Fracture Type: Conchoidal to uneven.
• Tenacity: Brittle.
• Luster Type: Adamantine to vitreous (on crystals), silky (fibrous aggregates), dull to earthy (massive forms).

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