mineral
Carnelian / Chalcedony
Silicon Dioxide (SiO2)
Hardness: 6.5-7 on Mohs scale; Color: Orange-brown, reddish-translucent; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline/cryptocrystalline); Cleavage: None; Conchoidal fracture
- Hardness
- 6
- Color
- Orange-brown, reddish-translucent
- Luster
- Vitreous to waxy
Identified More mineral →
Explore Carnelian / Chalcedony in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 on Mohs scale; Color: Orange-brown, reddish-translucent; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline/cryptocrystalline); Cleavage: None; Conchoidal fracture
Formation & geological history
Formed by the precipitation of silica from low-temperature water solutions filling cavities and fissures in volcanic and sedimentary rocks.
Uses & applications
Used in lapidary arts, jewelry (beads, cabochons, carvings), and as decorative polished tumbling stones.
Geological facts
Carnelian has been used for ornamental purposes for over 4,500 years; ancient Romans used carnelian signet rings to seal official documents because wax does not stick to it.
Field identification & locations
Look for a translucent, waxy to glass-like orange, reddish, or brownish pebble with smooth pitted or water-worn surface along riverbeds, gravel deposits, and beaches.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Septarian Pebble
Septarian nodule / Concretion
sedimentary
Sandstone with Mineral Veining or Crust
Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral