How to identify Galena

To correctly identify Galena (Lead(II) sulfide (PbS)), 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

   Lead-gray, often tarnishing to a dull gray or iridescent blue/purple.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Bright metallic, becoming dull on tarnished surfaces.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Typically massive, granular, or in well-formed cubic or cubo-octahedral crystals. Can also be fibrous.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Cubic, cubo-octahedral, or octahedral crystals are common. Also massive, granular, or fibrous aggregates.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Perfect cubic cleavage in three directions at 90 degrees, producing characteristic step-like fractures or breaking into cubes.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Hydrothermal veins, Mississippi Valley-type (MVT) deposits, contact metamorphic deposits, and less commonly in some igneous rocks.

Key Facts

Hardness

2.5-2.75 on the Mohs scale

Specific Gravity

7.4-7.6 (very high)

Crystal System

Isometric (cubic)

Color

Lead-gray, often tarnishing to dull gray or iridescent

Luster

Metallic

Transparency

Opaque

Fracture

Subconchoidal to uneven, but rarely observed due to perfect cleavage

Cleavage

Perfect cubic {001}

Composition

Lead(II) sulfide (PbS)

Physical characteristics

• Crystal Habit: Cubic, cubo-octahedral, octahedral, massive, granular, fibrous
• Cleavage Type: Perfect cubic {001}
• Fracture Type: Subconchoidal to uneven
• Tenacity: Brittle
• Luster Type: Metallic

Explore Galena