sedimentary
Glauconitic Sandstone
Glauconitic Sandstone (contains (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Hardness: 2-3 (glauconite) to 7 (quartz matrix); Color: Dull olive green to blue-green; Luster: Earthy to dull; Crystal structure: Monoclinic (microcrystalline); Specific gravity: 2.4-2.8
- Hardness
- 2-3 (glauconite) to 7 (quartz matrix)
- Color
- Dull olive green to blue-green
- Luster
- Earthy to dull
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 2-3 (glauconite) to 7 (quartz matrix); Color: Dull olive green to blue-green; Luster: Earthy to dull; Crystal structure: Monoclinic (microcrystalline); Specific gravity: 2.4-2.8
Formation & geological history
Formed in marine continental shelf environments through the chemical alteration of organic matter or mica in shallow water. Typically dates from the Cambrian to the Cenezoic eras.
Uses & applications
Used historically as a soil conditioner (greensand marl) due to potassium content, as a water softener, and occasionally as a green pigment for paints.
Geological facts
Glauconite is an 'indictor mineral' for marine environments; its presence almost always proves the rock was formed in seawater. It is the primary component of 'greensand' deposits.
Field identification & locations
Identify by its characteristic dull 'pea' green color and crumbly texture. Frequently found in the Atlantic Coastal Plain of the USA (especially New Jersey) and parts of Western Europe. Collectors look for high-concentration green grains.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary