sedimentary

Red Jasper

Microcrystalline quartz (SiO2) with Hematite (Fe2O3) impurities

Hardness: 6.5-7 (Mohs); Color: Deep opaque red to reddish-brown; Luster: Vitreous to dull; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Deep opaque red to reddish-brown
Luster: Vitreous to dull

Identified March 8, 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 when silica-rich fluids permeate sedimentary or volcanic rocks, depositing microcrystalline quartz. Its red color is derived from iron inclusions (hematite). It can be found in volcanic deposits or as water-worn pebbles in riverbeds.

Uses & applications

Commonly used for lapidary work, cabochons for jewelry, decorative carvings, tumbled stones for collectors, and historically as seal stones or amulets.

Geological facts

In ancient times, Red Jasper was known as the 'stone of endurance' and was frequently used by warriors for protection. It is a variety of chalcedony that is uniquely opaque due to its high mineral impurity content.

Field identification & locations

Identify in the field by its intense red color, extreme hardness (it will scratch glass), and lack of transparency even when held to a strong light. Common locations include Brazil, India, USA (sway-valleys), and South Africa.

Other sedimentary specimens

See all

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