sedimentary

Glauconitic Sandstone (or Greenstone)

Glauconitic Sandstone with Quartz

AI-generated identification · may be incorrect

Hardness: 6-7 (if quartz-rich); Color: Pale to olive green, white inclusions; Luster: Dull to earthy; Texture: Fine-grained to sandy; Cleavage: None (conchoidal fracture on quartz parts)

Hardness: 6-7 (if quartz-rich)
Color: Pale to olive green, white inclusions
Luster: Dull to earthy

Identified July 2, 2026More sedimentary →

Explore Glauconitic Sandstone (or Greenstone) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6-7 (if quartz-rich); Color: Pale to olive green, white inclusions; Luster: Dull to earthy; Texture: Fine-grained to sandy; Cleavage: None (conchoidal fracture on quartz parts)

Formation & geological history

Formed in marine environments through the alteration of mica and other minerals. This specimen appears to be a water-worn beach cobble from a coastal sedimentary formation.

Uses & applications

Primarily of interest to collectors or geologists; used as a soil amendment (greensand) or occasionally as building stone if found in large deposits.

Geological facts

The green color is typically caused by the mineral glauconite, an iron-potassium silicate that forms in shallow marine waters with slow sedimentation rates.

Field identification & locations

Identify by its distinctive sea-green patches against a lighter matrix and its rounded, water-worn beach context. Common in coastal areas with eroding cliffs containing sedimentary strata.