mineral

Kidney Stone

Calculus (calcium oxalate / uric acid)

Hardness varies from 3 to 5 on Mohs scale depending on composition. Colors range from yellow to brown or black, with an earthy or crystalline luster.

Identified October 23, 2026More mineral →

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

Physical properties

Hardness varies from 3 to 5 on Mohs scale depending on composition. Colors range from yellow to brown or black, with an earthy or crystalline luster.

Formed biologically within the kidneys through the precipitation and crystallization of minerals from urine over time.

Studied for medical diagnosis, metabolic analysis, and preventative health management.

Kidney stones have been documented in human mummies dating back thousands of years. They can vary in texture from smooth to jagged and spiky.

Identified through medical imaging or laboratory stone analysis. Commonly composed of calcium oxalate or uric acid.

Gneiss or Schist

Gneiss or Mica Schist with Garnet

Limonite

FeO(OH)•nH2O

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

Feldspar

Feldspar Group (Tectosilicate, e.g., KAlSi3O8)

Tumbled granite

Granite, a coarse-grained felsic intrusive igneous rock

Pegmatite with Tourmaline and Quartz

Igneous Pegmatite