Rock Identifier
Quartzite or Chert Pebble (SiO2 (dominant)) — metamorphic or sedimentary
metamorphic or sedimentary

Quartzite or Chert Pebble

SiO2 (dominant)

AI-generated identification · may be incorrect

Hardness: ~7 on Mohs scale. Color: brown, tan, gray with white veining. Luster: dull to slightly waxy. Crystal structure: microcrystalline or granular. Cleavage: none, conchoidal fracture.

Hardness
~7 on Mohs scale
Color
brown, tan, gray with white veining
Luster
dull to slightly waxy
Identified More metamorphic or sedimentary →
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Physical properties

Hardness: ~7 on Mohs scale. Color: brown, tan, gray with white veining. Luster: dull to slightly waxy. Crystal structure: microcrystalline or granular. Cleavage: none, conchoidal fracture.

Formation & geological history

Formed by metamorphism of sandstone (quartzite) or precipitation/diagenesis of silica (chert), subsequently smoothed by water action in a river or marine environment.

Uses & applications

Landscaping, decorative stone, occasionally tumbled for jewelry, or collected for its aesthetic appeal.

Geological facts

The white veins are likely quartz that filled fractures in the rock after its initial formation. Its smooth shape indicates a long history of transport by water.

Field identification & locations

Identified by its hardness (scratches glass), smooth water-worn surface, and quartz veining. Commonly found in riverbeds, beaches, and glacial deposits.

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Small quartz-rich mineral fragment

Quartz (SiO₂), possibly milky or chalcedonic quartz

mineral
Quartz vein fragment (Quartz, silicon dioxide (SiO₂), likely milky to translucent quartz with iron-oxide or clay inclusions) — mineral

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Quartz, silicon dioxide (SiO₂), likely milky to translucent quartz with iron-oxide or clay inclusions

mineral
Quartz-rich rock, possibly milky quartz or quartzite (Quartz (SiO₂); if quartzite, recrystallized quartz sandstone) — metamorphic

Quartz-rich rock, possibly milky quartz or quartzite

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metamorphic
Tumbled quartz pebble, possibly citrine or pale smoky quartz (Quartz (SiO₂), likely microcrystalline/tumbled material) — mineral

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Quartz (SiO₂), likely microcrystalline/tumbled material

mineral
Vesicular basalt with secondary mineralization (Mafic volcanic rock, chiefly plagioclase and pyroxene, with iron oxides and likely zeolite/calcite infillings) — igneous

Vesicular basalt with secondary mineralization

Mafic volcanic rock, chiefly plagioclase and pyroxene, with iron oxides and likely zeolite/calcite infillings

igneous