sedimentary

Glauconitic Sandstone

Glauconitic Sandstone with high Glauconite concentration ((K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)

AI-generated identification · may be incorrect

Hardness: 2-3 (glauconite) to 7 (quartz matrix); Color: dull green to grey-green; Luster: earthy to pearly; Structure: granular, often crumbly; Specific Gravity: 2.4-2.9

Hardness: 2-3 (glauconite) to 7 (quartz matrix)
Color: dull green to grey-green
Luster: earthy to pearly

Identified February 27, 2026More sedimentary →

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Physical properties

Hardness: 2-3 (glauconite) to 7 (quartz matrix); Color: dull green to grey-green; Luster: earthy to pearly; Structure: granular, often crumbly; Specific Gravity: 2.4-2.9

Formation & geological history

Formed in marine environments slow sedimentation rates during the Cambrian to Cenozoic eras, typically in 'greensand' deposits through the alteration of mica and organic matter in seawater.

Uses & applications

Used in water treatment as a natural ion exchanger (glauconite), as a slow-release soil fertilizer for potash, and historically as a green pigment for paints.

Geological facts

Commonly referred to as 'Greensand,' this rock is a vital indicator of ancient marine shelf environments and is frequently used by geologists for stratigraphic dating.

Field identification & locations

Identified by its distinctive olive-green color and coarse, sandy texture that rubs off easily. Found in coastal regions like the Atlantic Coastal Plain of the USA and parts of the UK.