Rockby LogoRockby

How to identify Green Selenite

Gypsum (variety Selenite)

Got a photo? Identify rocks instantly with the Rockby app

Open the app

To correctly identify Green Selenite (Gypsum (variety Selenite)), 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

    Ranges from pale mint green to deep emerald green, often translucent.

  2. 2

    Luster

    How the surface reflects light: metallic, vitreous, dull

    Vitreous (glassy) to pearly on cleavage surfaces.

  3. 3

    Texture

    Grain size and surface feel: coarse, fine, glassy

    Smooth to slightly fibrous, often with visible crystal faces.

  4. 4

    Crystal Form

    Shape of visible crystals or crystal faces

    Commonly tabular, prismatic, or acicular crystals. Can also form in 'desert rose' aggregates or fibrous masses (satin spar).

  5. 5

    Cleavage

    How it breaks: flat cleavage planes vs irregular fracture

    Perfect in one direction (pinacoidal), distinct in two others, leading to easy splitting into thin, flexible sheets.

  6. 6

    Geological Environment

    The rock formation and setting where it occurs

    Evaporite deposits, sedimentary basins, caves, and sometimes as a secondary mineral in hydrothermal veins or altered volcanic rocks.

Key Facts

Hardness
2 on the Mohs scale
Specific Gravity
2.31 - 2.33 g/cm³
Crystal System
Monoclinic
Color
Colorless, white, gray, yellow, brown, green (due to inclusions)
Luster
Vitreous to pearly
Transparency
Transparent to translucent
Fracture
Conchoidal to uneven
Cleavage
Perfect on {010}, distinct on {100} and {101}
Composition
Hydrous Calcium Sulfate (CaSO4·2H2O)

Physical characteristics

  • Crystal Habit: Tabular, prismatic, acicular, massive, fibrous (satin spar), granular, lamellar, rosettes (desert rose)
  • Cleavage Type: Perfect in one direction ({010}), distinct in two others ({100} and {101})
  • Fracture Type: Conchoidal to uneven
  • Tenacity: Sectile (can be cut with a knife), flexible in thin sheets
  • Luster Type: Vitreous to pearly

Explore Green Selenite

Identify rocks anywhere

Free on iOS, Android, and Web. Photo identification, full database, and your personal collection.

Open in app