Microcrystalline Quartz

Agate

Agate (Silicon Dioxide, SiO2)

Rounded brown chert or flint pebble

Microcrystalline quartz (chalcedony), SiO₂

Tumbled yellow-orange quartzite or jasper

Quartzite, chiefly microcrystalline quartz (SiO₂), possibly iron-oxide-stained jasper

Chalcedony (likely brown agate or flint)

Microcrystalline quartz, SiO₂; chalcedony, possibly iron-stained

Chert Pebble (Water-worn Quartz/Chalcedony)

Silicon Dioxide (SiO2)

Plume Agate

Cryptocrystalline Quartz (SiO2)

Blue Onyx (Agate)

Cryptocrystalline Quartz (SiO2)

Yellow Chalcedony (Carnelian / Agate Pebbles)

Silicon Dioxide (SiO2)

Tumbled yellow jasper or chert

Microcrystalline quartz (SiO₂), likely iron-stained jasper/chert

Yellow Chalcedony (Agate/Chert)

Cryptocrystalline Quartz (SiO2)

Agate Slice (Carnelian Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Polished brecciated jasper

Jasper, microcrystalline quartz (SiO₂), with iron oxides and pale chalcedony/quartz veins

Red jasper (possible)

Microcrystalline quartz, SiO₂, colored red by iron oxides; the image alone cannot confirm the identification.

Yellow Jasper

Cryptocrystalline Quartz (SiO2) with Goethite/Limonite inclusions

Polished heart-shaped blue chalcedony (likely dyed or treated)

Microcrystalline quartz, SiO₂; chalcedony variety, possibly blue lace agate or dyed quartz

Chalcedony with iron-oxide staining

Microcrystalline quartz (SiO₂), likely chalcedony or chert with limonite/goethite staining

Drusy quartz coating on volcanic rock

Quartz (SiO₂), likely druzy quartz on basalt or another mafic host

Tumbled pale chalcedony (likely quartz)

Microcrystalline quartz, SiO₂; possibly pale agate or quartz

Tree Agate

Quartz (SiO2) with Chlorite/Hornblende inclusions

Botryoidal Chalcedony (Agate)

Silicon Dioxide (SiO2)

Yellow Quartz / Chalcedony

Silicon Dioxide (SiO2)

Tumbled dark mineral on a polished brown stone slab

Likely quartz-rich chalcedony or jasper slab with a dark metallic mineral inclusion; exact identification is uncertain from the photograph

Tumbled yellow chalcedony (likely honey agate or yellow jasper)

Microcrystalline quartz, SiO₂; precise identification is uncertain from the photograph

Polished brown jasper pebble

Jasper, microcrystalline quartz (SiO₂) with iron-oxide impurities

Chert / Jasper

Microcrystalline Quartz (SiO2)

Banded Chert (Agate/Jasper blend)

Microcrystalline Quartz (SiO2)

Pink Dyed Agate Geode Slice

Cryptocrystalline Quartz (SiO2)

Agate

Banded Chalcedony (SiO2)

Red Jasper

Jasper (Silicon Dioxide, SiO2 with Iron oxide inclusions)

Chalcedony Pebble (Carnelian / Quartz Pebble)

Silicon Dioxide (SiO2)

Tumbled yellow-brown jasper

Jasper, microcrystalline quartz (SiO₂) with iron-oxide impurities

Tumbled Agate

Cryptocrystalline Silicon Dioxide (SiO2)

Raw pink chalcedony (likely pink agate/jasper)

Microcrystalline quartz, SiO₂ (chalcedony); impurities may include iron oxides and other silicates

Agate (Chalcedony Variation)

Silicon Dioxide (SiO2)

Banded Agate (specifically Lace Agate type)

Silicon Dioxide (SiO2)

Tumbled banded chert or jasper

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide impurities

Carved jasper bear figurine

Jasper, microcrystalline quartz (SiO₂), likely brecciated or orbicular jasper

Polished brecciated jasper

Jasper, microcrystalline quartz (SiO₂), commonly containing hematite, goethite, and clay minerals

Red jasper

Microcrystalline quartz (SiO₂), commonly colored by iron oxides

Tumbled brown jasper or chalcedony

Microcrystalline quartz (SiO₂), likely iron-stained jasper/chalcedony

Beach Pebble (Chalcedony / Chert)

Silicon Dioxide (SiO2)

Tumbled red-brown stone, likely jasper

Jasper, microcrystalline quartz (SiO₂), probably iron-oxide-bearing chert