Carnelian
Variety SiO2
Also called Cornelian
About it
Translucent orange to red chalcedony coloured by iron oxide; held to a light it glows evenly. India and Brazil are big sources, and much on sale is agate heated or dyed to that colour.
- Type
- Variety
- Group
- Quartz variety (chalcedony)
- Formula
- SiO2
- Hardness (Mohs)
- 6.5–7
- Specific gravity
- 2.57–2.64
- Streak
- white
- Lustre
- waxy, vitreous (glassy)
- Crystal system
- Trigonal
- Colours
- orange, red-orange, reddish brown
- Transparency
- translucent
- Cleavage and fracture
- none; conchoidal to uneven fracture
Typical values: real specimens vary. For more, see mindat.org.