How to identify Galena

To correctly identify Galena (Galena (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 duller gray or iridescent blue/purple.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Bright metallic, often very reflective.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Typically massive, granular, or in well-formed cubic or cubo-octahedral crystals. Can feel heavy due to high density.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Cubic, cubo-octahedral, or octahedral crystals are common. Also occurs as massive, granular, or fine-grained 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 (mesothermal to epithermal), Mississippi Valley-type (MVT) deposits, sedimentary exhalative (SEDEX) deposits, contact metamorphic deposits, and less commonly in igneous rocks. Often found with sphalerite, chalcopyrite, pyrite, quartz, calcite, and fluorite.

Key Facts

Hardness

2.5-2.75 on Mohs scale

Specific Gravity

7.4-7.6 g/cm³ (very heavy)

Crystal System

Isometric (cubic)

Color

Lead-gray, often tarnishing to duller gray or iridescent blue/purple

Luster

Metallic

Transparency

Opaque

Fracture

Subconchoidal to uneven, but typically dominated by cleavage

Cleavage

Perfect cubic in three directions at 90 degrees

Composition

Lead sulfide (PbS)

Physical characteristics

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

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