Opaque, fine-grained variety of chalcedony containing up to 20% foreign materials that determine its color and pattern. Color: Red, brown, yellow, green. Luster: Dull to vitreous. Streak: White to brown. Cleavage: None conchoidal fracture. Hardness: 6.5-7. Transparency: Opaque. Crystal system: Hexagonal Trigonal. Chemical formula: SiO₂. Specific gravity: 2.58-2.91. Formation: Forms from silica-rich sediments or volcanic ash, often replacing organic material during diagenesis. Common geological settings: Worldwide; found in volcanic and sedimentary environments. Common look-alikes and related entries: Chert, Flint, Carnelian.
Agate vs Jasper — Compare observable properties and safer field tests.
Jasper vs Chert — Compare observable properties and safer field tests.
Sources, scope & corrections
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.
Editorial owner
GeoMiner
Last updated
2026-03-30T14:36:42.834181+00:00
Review status
Published; not independently peer-reviewed
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.
Opaque, fine-grained variety of chalcedony containing up to 20% foreign materials that determine its color and pattern.
How can you identify Jasper?
Compare several properties rather than relying on colour alone. This entry records colour: Red, brown, yellow, green; lustre: Dull to vitreous; streak: White to brown; Mohs hardness: 6.5-7; cleavage: None conchoidal fracture; crystal system: Hexagonal Trigonal; transparency: Opaque. Confirm an important identification with additional field tests or qualified laboratory work.
How does Jasper form?
Forms from silica-rich sediments or volcanic ash, often replacing organic material during diagenesis.
Where is Jasper commonly found?
Worldwide; found in volcanic and sedimentary environments.
What is Jasper commonly confused with?
Jasper may be confused with Chert, Flint, Carnelian. Compare multiple diagnostic properties because colour and surface appearance can overlap.
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