Microcrystalline Quartz

Likely reddish-brown chert or jasper fragment

Microcrystalline quartz (SiO₂), possibly iron-oxide-bearing jasper

Tumbled ocean jasper (orbicular jasper), likely brecciated variety

Jasper: microcrystalline quartz (SiO₂) with iron-oxide staining and other silicate inclusions

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Polished multicolored jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), likely iron- and manganese-stained chert

Polished red jasper beads

Jasper, microcrystalline quartz (SiO₂), colored mainly by iron oxides

Polished brecciated jasper

Jasper; microcrystalline quartz (SiO₂) with iron-oxide staining and dark mineral fragments

Red jasper pebble (probable)

Jasper; microcrystalline quartz (SiO₂) colored mainly by iron oxides

Rounded chert or jasper pebble

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

Polished red jasper mushroom carving

Jasper, microcrystalline quartz (SiO₂), colored chiefly by iron oxides

Likely tumbled jasper or chert pebble

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

Tumbled jasper or chalcedony

Microcrystalline quartz (SiO₂), likely brown jasper/chalcedony

Petrified Wood and Mixed Rocks

Silicified Wood (SiO2)

Tumbled jasper or chalcedony

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

Red jasper (likely brecciated or orbicular jasper)

Microcrystalline quartz, SiO₂, colored mainly by iron oxides

Brecciated jasper (likely ocean jasper or red jasper)

Microcrystalline quartz, SiO₂, with iron-oxide pigments and breccia cement

Flint or chert flake

Microcrystalline quartz (SiO₂), commonly chert/flint

Chert / Flint (with Jasper inclusions)

Microcrystalline Quartz (SiO2)

Chert (or Chalcedony)

Microcrystalline Quartz (SiO2)

Tumbled chalcedony (likely pale agate or quartz)

Chalcedony, microcrystalline SiO₂

Red Jasper (Quartz)

SiO2 (Silicon Dioxide with Iron Oxide inclusions)

Tumbled yellow quartz (likely citrine or yellow chalcedony)

Quartz, SiO₂; variety uncertain from image

Agate in Rhyolite

Silicon Dioxide (Quartz/Chalcedony) in Volcanic Rock matrix

Polished jasper pebble

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

Red Jasper

Silicon Dioxide with Iron inclusions (SiO2)

Rounded pinkish pebble, likely quartzite or microcrystalline quartz

Quartzite; predominantly quartz (SiO₂), possibly with iron-oxide staining

Dyed or color-enhanced agate/microcrystalline quartz bead

Chalcedony (microcrystalline SiO₂), likely agate

Chalcedony / Quartz Pebble

Silicon Dioxide (SiO2)

Tumbled chalcedony or quartz pebble

Microcrystalline quartz, SiO₂ (likely chalcedony; exact identification requires testing)

Weathered quartz-rich pebble, possibly jasper or chert

Microcrystalline quartz (SiO₂), with iron-oxide staining and possible clay/mineral inclusions

Tumbled yellow-orange chalcedony (possibly yellow jasper)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide coloration

Polished agate (likely chalcedony)

Microcrystalline quartz, SiO₂; agate is banded chalcedony

Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Polished red jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides

Polished bloodstone (heliotrope) cabochon

Chalcedony, microcrystalline quartz (SiO₂), with iron-oxide inclusions; the pictured stone may be a mottled jasper–chalcedony variety

Tumbled mottled stone, likely serpentine or jasper

Probable serpentine-group mineral (Mg₃Si₂O₅(OH)₄) or fine-grained jasper; identification is limited by the image

White chalcedony (possibly milky quartz) cabochon

Chalcedony, microcrystalline SiO₂; appearance may also represent milky quartz or synthetic imitation

Tumbled chert or flint

Microcrystalline quartz (SiO₂), commonly termed chert; dark varieties are called flint

Tumbled blue-gray stone, possibly chalcedony or quartzite

Likely microcrystalline quartz (SiO₂), but the image is insufficient for confident identification

Tumbled brown chalcedony (likely chert or agate)

Microcrystalline quartz, SiO₂ (chalcedony); exact variety is uncertain from the image

Chert (Flint)

Silicon Dioxide (SiO2)

Weathered agate or chalcedony nodule

Microcrystalline quartz (SiO₂), likely agate/chalcedony with iron-oxide staining

Chalcedony Geode Part (Agate/Quartz)

Silicon Dioxide (SiO2)