Jasper (Chocolate Jasper)
Quartz (Variety: Jasper) · Semi-Precious Gemstone / Decorative Stone
Crystal System
Trigonal; Microcrystalline (Cryptocrystalline) aggregate with no visible external crystal faces
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2 (Silicon Dioxide) with Fe2O3 (Iron Oxide) inclusions
Formation Process
Primarily sedimentary through the silicification of fine-grained volcanic ash or clays, or hydrothermal deposition of silica within rock cavities
About This Crystal
An opaque, microcrystalline variety of quartz showing a deep reddish-brown to 'chocolate' brown color. It has a smooth, slightly waxy to dull luster with potential fine pitting on the surface and a sub-conchoidal fracture profile.
Physical Characteristics
Color: Dark Brown; Streak: White; Cleavage: None; Fracture: Conchoidal to uneven; Specific Gravity: 2.58 - 2.91; Tenacity: Brittle; Fluorescence: Generally inert
Optical Properties
Refractive Index: 1.544 - 1.553; Opaque (does not transmit light even on thin edges); No pleochroism or dispersion visible due to opacity
Hardness & Durability
Origin Region
Worldwide; notable sources in Madagascar, South Africa, Australia, and the Western USA, typically in sedimentary or volcanic environments
Hardness & Durability
Mohs Hardness: 6.5 - 7.0; High toughness due to interlocking microcrystalline structure; Stable under most conditions
Care & Maintenance
Safe to clean with warm soapy water; resistant to most household chemicals but can be scratched by harder stones like topaz or sapphire; store separately to prevent surface abrasions
Rarity & Value
Common; Value is generally low, determined by the polish quality, size, and interesting patterns; treatments like dyeing are occasionally used but rare for brown varieties
Special Characteristics
Opaque nature distinguishes it from chalcedony; high iron content provides the earth-toned pigmentation; often found as water-worn pebbles in riverbeds
Lore & History
Historically used as a 'warrior's stone' for protection and grounding; traditionally associated with the Root Chakra in crystal healing lore; utilized since antiquity for cylinder seals and amulets.