Microcrystalline Quartz

Jasper

Silicon dioxide (SiO2)

Chert / Microcrystalline Quartz

Silicon Dioxide (SiO2)

Chert / Microcrystalline Quartz

Chert (SiO2)

Chert or microcrystalline quartz fragment

Chert; cryptocrystalline SiO₂, possibly chalcedony-rich

Microcrystalline Quartz (Chert/Agate)

Silicon Dioxide (SiO2)

Chert / Microcrystalline Quartz

Chert (SiO2)

Chert / Microcrystalline Quartz

Silicon Dioxide (SiO2)

Chert (or Microcrystalline Quartz)

Chert (Silicon Dioxide, SiO2)

Mookite

Radiolarian Chert (SiO2)

Red Jasper (River Pebble)

Silicon Dioxide (SiO2) with hematite impurities

Red Jasper

Jasper (SiO2) with Hematite (Fe2O3) inclusions

Mookaite Jasper

Silicified radiolarit

Agate Geode

Silicon dioxide (Chalcedony/Quartz), SiO2

Picture Jasper

Silicon dioxide with iron oxide impurities (SiO2)

Black Jasper (Black Onyx substitute)

Silicon Dioxide (SiO2) with carbonaceous impurities

Yellow Jasper

Chalcedony (Silicon Dioxide, SiO2)

Gray chalcedony (microcrystalline quartz)

Chalcedony, SiO₂; a cryptocrystalline variety of quartz

Jasper

Jasper (Silicon Dioxide, SiO2)

Jasper River Pebble

Silicon Dioxide (SiO2)

Red Jasper with Quartz

SiO2

Ocean Jasper

Orbicular Jasper / SiO2

Agate

SiO2

Dyed Blue Agate Druzy Pendant

Quartz / Chalcedony (SiO2) with artificial color treatment

Gray chalcedony (microcrystalline quartz)

Chalcedony, SiO₂; likely common gray/blue-gray variety

Yellow Chert (Microcrystalline Quartz)

Chert / SiO2 (Silicon Dioxide)

Red Jasper (Microcrystalline Quartz)

SiO2 (Silicon Dioxide) with Iron Oxide inclusions

Banded Agate (Crazy Lace/Mexican Agate Variety)

Silicon Dioxide (SiO2)

Ocean Jasper

Orbicular Jasper, Chalcedony (SiO2)

Fossil Coral

Rugosa or Tabulata coral fossilized in Agate/Chalcedony

Chert (Flint Arrowhead)

Silicon Dioxide (SiO2)

Green Aventurine

Quartz with Fuchsite inclusions (SiO2)

Dalmatian stone

Dalmatian jasper (commercial name); commonly spotted rhyolite or related feldspar-rich rock, not true jasper

Chalcedony Geode

Silicon Dioxide (SiO2)

Banded chert (banded microcrystalline quartz)

Chert, chiefly microcrystalline quartz (SiO₂), with iron-oxide and clay impurities

Banded Agate Geode (with Microcrystalline Quartz)

Silicon Dioxide (SiO2) - variety Chalcedony/Agate

Jasper (Iron-rich Microcrystalline Quartz)

Silicon Dioxide (SiO2) with Hematite inclusions

Polished brecciated jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with iron-oxide coloring

Dalmatian jasper (Dalmatian stone)

Commercially called Dalmatian jasper; typically a feldspar-rich rock with dark arfvedsonite or tourmaline-group inclusions, rather than true jasper

Polished reddish-brown stone bead, possibly jasper

Likely iron-rich microcrystalline quartz (jasper; SiO₂), but the image is not sufficient for a confident identification

Dalmatian jasper (Dalmatian stone)

Feldspar-rich porphyritic igneous rock, commonly sold as Dalmatian jasper; dark spots are mainly amphibole and/or tourmaline minerals

Agate Breccia

Brecciated Chalcedony (SiO2)

Small rough jasper and agate specimens (identification tentative)

Microcrystalline quartz: chalcedony, SiO₂; opaque varieties are commonly called jasper, while translucent or banded varieties are agate.