sedimentary

Pyritic Sandstone

Clastic Sedimentary Rock (Pyrite-bearing Sandstone)

Hardness: 6-6.5 (for pyrite grains), 6-7 (for quartz matrix); Color: Grey with golden-metallic specks; Luster: Metallic to dull; Crystal structure: Cubic or pyritohedron grains within a granular matrix; Cleavage: None/Indistinct; Specific Gravity: 2.6-5.0 depending on pyrite concentration.

Hardness: 6-6
Color: Grey with golden-metallic specks
Luster: Metallic to dull

Identified June 10, 2026More sedimentary →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed through the lithification of sand-sized mineral grains. The pyrite likely formed in a reducing (oxygen-poor) environment, such as a marine basin or swamp, where iron-rich waters reacted with sulfide-producing bacteria during or after deposition.

Uses & applications

Primarily of interest to geological collectors. Rarely used as an iron or sulfur ore due to impurities. Can be used in decorative landscaping if stable, though pyrite may oxidize over time.

Geological facts

The metallic gold-colored flecks are iron disulfide (Pyrite), famously known as 'Fool's Gold' because it has deceived many prospectors into thinking they found real gold.

Field identification & locations

Identify by its granular, 'sandpaper' texture and the presence of tiny, metallic, brass-yellow glints that do not scratch with a copper penny. Found in sedimentary basins worldwide. When wet, it may produce a faint sulfurous smell.

Other sedimentary specimens

See all

Sandstone or Siltstone

Arenite (if sandstone)

Sedimentary

Sandstone

Arenite (primarily SiO2)

sedimentary

Chert Breccia

Brecciated Chert (Microcrystalline Silica)

sedimentary

Sandstone Grain

Clastic Sedimentary Rock Grain (SiO2 dominated)

sedimentary

Shale or Slaty Mudstone

Argillaceous sedimentary rock

sedimentary

Sandstone

Arenite

sedimentary