
mineral
Dendritic jasper/chalcedony
Silica-rich microcrystalline quartz (SiO₂) with manganese-oxide dendrites
AI-generated identification · may be incorrectHardness about 6.5–7 Mohs; tan to ochre, opaque, with black branching fern-like patterns. Dull to slightly waxy luster, cryptocrystalline structure, no visible cleavage, and typical specific gravity near 2.6.
Identified More mineral →
Explore Dendritic jasper/chalcedony in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 6.5–7 Mohs; tan to ochre, opaque, with black branching fern-like patterns. Dull to slightly waxy luster, cryptocrystalline structure, no visible cleavage, and typical specific gravity near 2.6.
Formation & geological history
Silica-rich groundwater filled fractures or cavities in volcanic or sedimentary host rock; manganese and iron oxides crystallized in branching dendritic patterns. The specimen’s precise geological age cannot be determined from the image.
Uses & applications
Used as a lapidary stone for cabochons, carvings, tumbled stones, and display pieces; it is generally decorative rather than industrial. Value depends on contrast, polish, pattern, and size.
Geological facts
The fern-like markings are mineral dendrites, not fossils or organic plant material. Similar material is commonly sold as dendritic jasper, dendritic agate, or scenic stone.
Field identification & locations
Identify by testing for glass-scratching hardness, examining the natural branching surface patterns, and checking that patterns lie within the stone rather than on a coating. Common sources include India, Madagascar, Brazil, Mexico, and the western United States.
More like this
Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous