Mineral (Chalcedony)

Tumbled brown jasper

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

Quartz-rich rock fragment

Microcrystalline quartz (SiO₂), possibly chalcedony or quartz-bearing breccia

Polished banded agate (likely petrified wood)

Microcrystalline quartz (SiO₂); possibly silicified wood

Polished reddish-brown gemstone, likely carnelian

Carnelian: chalcedony, microcrystalline quartz (SiO₂), colored mainly by iron oxides

Red jasper (likely)

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

Tumbled carnelian (likely)

Cryptocrystalline quartz, SiO₂; reddish chalcedony colored mainly by iron oxides

Tumbled brown agate (probable)

Microcrystalline quartz, SiO₂ (chalcedony/agate)

Tumbled orange chalcedony (probable carnelian)

Cryptocrystalline quartz, SiO₂; reddish-orange variety commonly called carnelian

Tumbled red jasper (likely)

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

Tumbled jasper

Microcrystalline quartz (SiO₂), commonly iron-oxide-bearing chalcedony

Orbicular jasper (likely ocean jasper)

Silicified volcanic rock composed chiefly of microcrystalline quartz/chalcedony (SiO₂), with iron-oxide and other mineral inclusions

Tumbled jasper or agate

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

Banded Chert

Microcrystalline Quartz (SiO2)

Polished dendritic agate pebble

Chalcedony (microcrystalline SiO₂) with dark manganese- or iron-oxide dendrites

Tumbled banded agate (likely chalcedony)

Banded microcrystalline quartz, SiO₂; chalcedony variety

Grape Agate

Botryoidal Amethystine Chalcedony (SiO2)

Polished/tumbled agate (likely carnelian or iron-stained chalcedony)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide inclusions

Green glassy mineral specimen, likely nephrite or serpentine

Indeterminate from image; possible nephrite jade (interlocking amphibole, chiefly Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂) or green serpentine (Mg₃Si₂O₅(OH)₄)

Polished/tumbled brown-and-white mineral fragment

Indeterminate; possibly quartz-rich jasper, brecciated jasper, or an iron-stained quartz mineral

Agate (Carnelian / Fire Agate nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Green chalcedony (possibly jade or serpentine)

Microcrystalline quartz, SiO₂; exact identification is uncertain from the image

Honey calcite (likely calcite-rich marble or vein fragment)

Calcite, calcium carbonate (CaCO₃)

Crazy Lace Agate

SiO2

Dendritic Agate

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

Petrified Wood

Silicified wood (Quartz / Chalcedony replacement)

Agate

Silicon dioxide (Chalcedony), SiO2

Green Jasper

Microcrystalline Quartz (Chalcedony), SiO2

Agate

Silicon Dioxide (Chalcedony), SiO2

Likely tumbled or cut quartz/chalcedony fragment

Silicon dioxide (SiO₂), probably microcrystalline quartz or quartz

Dyed agate slice

Microcrystalline quartz (SiO₂), typically banded chalcedony

Tumbled Moss Agate

Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide

Chalcedony (likely agate or chert)

Microcrystalline quartz, SiO₂

Chalcedony (Agate / Quartz Nodule)

Silicon Dioxide (SiO2)

Red jasper (likely)

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

Polished dendritic agate pendant

Microcrystalline quartz (SiO₂), with dark manganese- or iron-oxide dendrites

Iron-stained chalcedony (possible agate/jasper)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide staining

Chrysoprase

Chalcedony (cryptocrystalline silica containing nickel); Chemical Formula: SiO2 with Ni impurities

Agate

Silicon Dioxide (Chalcedony), SiO2

Fancy Jasper

Chalcedony (cryptocrystalline quartz) with inclusions

Quartz (Chalcedony/Agate nodule)

Silicon dioxide (SiO2)

Dyed Agate

SiO2

Chrysoprase

Silicon dioxide (SiO2) with nickel impurities