Translucent reddish-orange variety of chalcedony colored by iron oxide. One of the oldest known gemstones. Color: Red, orange, reddish-brown. Luster: Waxy to vitreous. Streak: White. Cleavage: None. Hardness: 6.5-7. Transparency: Translucent. Crystal system: Hexagonal Trigonal. Chemical formula: SiO₂. Specific gravity: 2.59-2.61. Formation: Forms from silica-rich solutions depositing in cavities, colored by iron oxide inclusions. Common geological settings: India, Brazil, Uruguay, Madagascar; found in volcanic rocks and alluvial gravels. Common look-alikes and related entries: Jasper, Agate, Sard.
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These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.
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Last updated
2026-03-30T14:37:37.344949+00:00
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IMA–CNMNC List of Mineral Names — International Mineralogical Association. Official mineral-name, nomenclature, and classification records.
Mineral ID Key — Mineralogical Society of America. Physical-property identification methods, repeat-testing guidance, and limitations.
Translucent reddish-orange variety of chalcedony colored by iron oxide. One of the oldest known gemstones.
How can you identify Carnelian?
Compare several properties rather than relying on colour alone. This entry records colour: Red, orange, reddish-brown; lustre: Waxy to vitreous; streak: White; Mohs hardness: 6.5-7; cleavage: None; crystal system: Hexagonal Trigonal; transparency: Translucent. Confirm an important identification with additional field tests or qualified laboratory work.
How does Carnelian form?
Forms from silica-rich solutions depositing in cavities, colored by iron oxide inclusions.
Where is Carnelian commonly found?
India, Brazil, Uruguay, Madagascar; found in volcanic rocks and alluvial gravels.
What is Carnelian commonly confused with?
Carnelian may be confused with Jasper, Agate, Sard. Compare multiple diagnostic properties because colour and surface appearance can overlap.
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