Gemstone profile and identification guide
Fire Chalcedony
Fire chalcedony is an orange-red chalcedony trade variety distinguished by body color rather than interference iridescence.
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Overview
Fire chalcedony is an orange-red chalcedony trade variety distinguished by body color rather than interference iridescence.
Did you know? Fire chalcedony and fire agate are distinct lapidary categories in practice.
Use this profile as a collector reference and educational guide for quick on-page comparison, then validate with the interactive identification system.
Identification
Name: Fire Chalcedony
Scientific classification: Silicate (Chalcedony Quartz Variety)
Hardness: 7 Mohs
Transparency: translucent
Lustre: waxy
Crystal system: Trigonal (microcrystalline aggregate)
Primary colour: Orange
Secondary colour: Red Orange
Colour family: Oranges & Yellows
Uniform warm body color without strong iridescent layer effects helps separate it from true fire agate.
Verification Status
Status: verified-core-fields
Reference priority: GIA, Gem-A, Mindat, International Gem Society
Core identity, locality, and physical-property fields reviewed against standard gemological references.
Trade-name entries include treatment/composition disclosures where applicable.
Physical Properties
Hardness category: hard
Hardness value: 7 Mohs
Chemical composition: Silicon dioxide (SiO2) with iron-related color
Crystal system: Trigonal (microcrystalline aggregate)
Common locations: Mexico, United States, Brazil, India
Learn more: Gem-A gemstone education resources.
Colour Variations
Warm orange to red-orange chalcedony body color, generally without true fire-agate interference layers.
Optical effects: None specified in the current dataset.
Detailed Gemology
Mineral species: Quartz (chalcedony variety)
Mineral group: Quartz group
Chemical formula: Silicon dioxide (SiO2) with iron-related color
Mohs hardness: 7
Crystal system: Trigonal (microcrystalline aggregate)
Lustre: waxy
Transparency: translucent
Streak: White
Cleavage: None
Fracture: Conchoidal
Specific gravity: 2.58-2.64
Refractive index: 1.53-1.54
Optical phenomena: None typically diagnostic
Colour range: Orange, red-orange, brown-orange
Common inclusions: Iron oxides, cloudy zoning, microfractures
Geological environment: Silica-rich volcanic and sedimentary chalcedony environments
Principal mining regions: Mexico, United States, Brazil, India
Important commercial sources: Commercial fire chalcedony rough is sourced from chalcedony-producing regions including Mexico and the U.S.
Historical significance: Modern lapidary trade color descriptor.
Common treatments: Heat and dyeing may occur.
Synthetic or imitation forms: Dyed chalcedony and glass are common imitations.
Common look-alikes: Carnelian, dyed agate, orange glass
Jewellery uses: Used in cabochons, beads, and carved lapidary products.
Care recommendations: Good quartz durability; use normal gemstone care and avoid hard impact on thin pieces.
Cross-check profile data with GIA Gem Encyclopedia and Mindat entry for Fire Chalcedony.
Formation
Forms by silica deposition with iron-bearing coloration in volcanic and sedimentary silica systems.
Origin
Commercial fire chalcedony rough is sourced from chalcedony-producing regions including Mexico and the U.S.
Uses
Best for: Used in cabochons, beads, and carved lapidary products.
Ideal uses: Cabochon and bead jewelry emphasizing warm translucent body color.
Care
Good quartz durability; use normal gemstone care and avoid hard impact on thin pieces.
Need another candidate? Use advanced gemstone search or return to the identification guide.
Related gemstones by colour
Related gemstones by hardness
Gemstones from the same mineral family
Commonly confused gemstones
Fire Chalcedony FAQ
How can I identify Fire Chalcedony?
Compare hardness (7 Mohs), crystal system (Trigonal (microcrystalline aggregate)), colour profile, and lustre (waxy) with your sample. Then cross-check related gemstones listed above.
What colour range does Fire Chalcedony appear in?
Warm orange to red-orange chalcedony body color, generally without true fire-agate interference layers.
Where is Fire Chalcedony commonly used?
Cabochon and bead jewelry emphasizing warm translucent body color.. For maintenance, follow the care guidance in this profile.
Scientific References
GIA: general gemstone identity (reviewed) - Batch 05 factual verification pass.
Gem-A: gemological terminology and testing references (reviewed) - Batch 05 factual verification pass.
Mindat: mineral species and principal localities (reviewed) - Batch 05 factual verification pass.
International Gem Society: gem trade context and treatment overview (reviewed) - Batch 05 factual verification pass.