How to identify Quartz with Galena

To correctly identify Quartz with Galena (SiO2 (Quartz) with PbS (Galena)), 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

   Quartz: Colorless, white, gray, or various other colors depending on impurities. Galena: Lead-gray to silvery-gray.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Quartz: Vitreous (glassy). Galena: Metallic.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Quartz: Crystalline, granular, or massive. Galena: Crystalline, often cubic or granular.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Quartz: Hexagonal prisms with pyramidal terminations, massive, or cryptocrystalline. Galena: Cubic, cubo-octahedral, or octahedral crystals; also massive or granular.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Quartz: None (conchoidal fracture). Galena: Perfect cubic cleavage in three directions at 90 degrees.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Hydrothermal veins, replacement deposits, and skarns, often associated with igneous intrusions or metamorphic terrains.

Key Facts

Hardness

Quartz: 7 (Mohs); Galena: 2.5-2.75 (Mohs)

Specific Gravity

Quartz: 2.65 g/cm³; Galena: 7.4-7.6 g/cm³ (very heavy)

Crystal System

Quartz: Trigonal; Galena: Isometric (Cubic)

Color

Quartz: Colorless, white, gray, purple, pink, yellow, brown, black; Galena: Lead-gray to silvery-gray

Luster

Quartz: Vitreous; Galena: Metallic

Transparency

Quartz: Transparent to opaque; Galena: Opaque

Fracture

Quartz: Conchoidal; Galena: Subconchoidal to uneven

Cleavage

Quartz: None; Galena: Perfect cubic in three directions at 90 degrees

Composition

Quartz: Silicon dioxide (SiO2); Galena: Lead sulfide (PbS)

Physical characteristics

• Crystal Habit: Quartz: Prismatic, massive, granular, cryptocrystalline; Galena: Cubic, cubo-octahedral, octahedral, massive, granular
• Cleavage Type: Quartz: Absent; Galena: Perfect {001}
• Fracture Type: Quartz: Conchoidal; Galena: Subconchoidal to uneven
• Tenacity: Quartz: Brittle; Galena: Brittle
• Luster Type: Quartz: Vitreous; Galena: Metallic

Explore Quartz with Galena