mineral
Sardonyx or Carnelian Agate
Silicon Dioxide (SiO2) with iron impurities
Hardness: 6.5-7 (Mohs scale), Color: Reddish-orange to brownish-red, Luster: Vitreous to waxy, Crystal structure: Trigonal/microcrystalline, Specific gravity: 2.58-2.64
- Hardness
- 6
Identified More mineral →
Explore Sardonyx or Carnelian Agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Reddish-orange to brownish-red, Luster: Vitreous to waxy, Crystal structure: Trigonal/microcrystalline, Specific gravity: 2.58-2.64
Formation & geological history
Formed by the deposition of silica from groundwater in the cavities of igneous rocks. The reddish color is due to the presence of iron oxide (hematite) during formation.
Uses & applications
Used primarily in jewelry making for beads, cabochons, and cameos. Frequently used as a grounding stone in metaphysical practices.
Geological facts
In ancient times, Roman soldiers wore carnelian engraved with figures of deities for courage and protection. It is a variety of chalcedony.
Field identification & locations
Identified by its translucent to opaque reddish-orange hue and waxy surface. Often found in riverbeds or volcanic regions. Collectors look for uniform color and lack of heavy fracturing.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock
Granite
Granite (Phaneritic intrusive igneous rock)
igneous