metamorphic
Quartzite (with possible Calcite/Limestone weathering)
Quartzite (primarily SiO2)
Hardness: 7 (cannot be scratched by steel); Color: White to grey with tan/orange iron staining; Luster: Vitreous to dull; Crystal structure: Non-foliated granoblastic; Cleavage: None (conchoidal fracture).
- Hardness
- 7 (cannot be scratched by steel)
- Color
- White to grey with tan/orange iron staining
- Luster
- Vitreous to dull
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (cannot be scratched by steel); Color: White to grey with tan/orange iron staining; Luster: Vitreous to dull; Crystal structure: Non-foliated granoblastic; Cleavage: None (conchoidal fracture).
Formation & geological history
Formed through the metamorphism of quartzose sandstone under extreme heat and pressure. The specimen shows signs of chemical weathering and iron oxidation from ground water contact, possibly deposited in a decorative garden setting.
Uses & applications
Used primarily as construction aggregate, railway ballast, and decorative landscaping stone. High-quality quartzite is also used in the glass and ceramic industries.
Geological facts
Quartzite is so durable that it often survives intense weathering that destroys softer stones like limestone. When it breaks, the fractures cut across the individual sand grains rather than around them.
Field identification & locations
Identify in the field by its superior hardness (scratches glass) and lack of reaction to weak acid. This specimen's coarse texture suggests a prominent crystalline structure often found in the Appalachian region or glaciated areas of North America.
More like this
