sedimentary

Sandstone Concretion

Sedimentary Concretion (Quartz matrix)

Hardness 6-7 on Mohs scale, brown to grey color, dull luster, massive amorphous crystal structure, no cleavage, specific gravity around 2.65.

Identified November 13, 2026More sedimentary →

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

Physical properties

Hardness 6-7 on Mohs scale, brown to grey color, dull luster, massive amorphous crystal structure, no cleavage, specific gravity around 2.65.

Formed through the precipitation of mineral cement within the pores of sedimentary rock strata, often around a nucleus, over millions of years.

Used primarily as decorative collector specimens, garden landscaping stones, or geological study materials.

These spherical or discoidal masses often weather out of softer surrounding rock layers due to differential erosion.

Identify by its distinct rounded or spherical shape and uniform sandy texture; commonly found in sedimentary basins worldwide.

Fossil-bearing concretion, possibly containing a fossil shell or other organic inclusion

Calcareous concretion; exact fossil and host-rock composition are not identifiable from the image

Sandstone or Siltstone

Arenite (if sandstone)

Fossiliferous Sedimentary Rock

Sedimentary limestone with invertebrate fossil imprint

Shale

Fissile Sedimentary Rock

Sandstone

Arenite

Shale

Clastic sedimentary rock