mineral
Yellow Quartz (Chert/Chalcedony)
Silicon Dioxide (SiO2) with iron inclusions
AI-generated identification · may be incorrectHardness: 7 on Mohs scale; Color: Yellow-brown to tan; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.7
- Hardness
- 7 on Mohs scale
- Color
- Yellow-brown to tan
- Luster
- Waxy to vitreous
Identified More mineral →
Explore Yellow Quartz (Chert/Chalcedony) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale; Color: Yellow-brown to tan; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.7
Formation & geological history
Formed through the accumulation of silica-rich fluids in sedimentary environments or as secondary fillings in vesicles. Often weathered into smooth pebbles by water action.
Uses & applications
Used in landscaping, tumble polishing for hobbyists, and occasionally for lapidary work or as flint for fire-starting.
Geological facts
This specimen shows the characteristic waxy luster of cryptocrystalline quartz. It is often referred to as 'river chert' when found in alluvial deposits. Iron oxides give it the yellow or brownish tint.
Field identification & locations
Look for a smooth, waxy feel and the inability to be scratched by a steel knife. Common in riverbeds, glacial tills, and desert pavements worldwide.
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