Mineral (Specifically A Variety Of Chalcedony, Which Is A Microcrystalline Quartz)

Jasper (Iron-stained Chert)

Silicon Dioxide (SiO2) with impurities of Hematite or Goethite

Chert (specifically Red Chert or Jasper)

Microcrystalline Quartz (SiO2)

Blue Chalcedony

Silicon Dioxide (SiO2)

Red jasper

Microcrystalline quartz (SiO₂), colored mainly by iron oxides

Polished banded jasper

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

Polished agate (likely)

Banded chalcedony, a microcrystalline variety of quartz (SiO₂)

K2 Jasper (K2 Granite)

Azurite in Granite (Biotite Granite with Azurite inclusions)

Tumbled jasper, likely red jasper

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

Tumbled yellow-brown jasper or chalcedony

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

Tumbled agate/chalcedony (likely moss or plume agate)

Microcrystalline quartz, SiO₂, chiefly chalcedony with possible iron-oxide inclusions

Tumbled red jasper

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

Tumbled red jasper

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

Polished brecciated jasper (likely Apache tear–type iron-rich jasper)

Jasper, microcrystalline quartz (SiO₂), colored by hematite/goethite and other iron oxides

Polished brecciated jasper

Microcrystalline quartz (SiO₂), commonly with iron-oxide and clay-mineral inclusions

Dyed Blue Agate Slice

Silicon Dioxide (Chalcedony variety), $SiO_2$

Geode with Quartz and possibly Jasper/Hematite

Quartz (SiO2) and Chalcedony (cryptocrystalline SiO2), possibly stained by iron oxides

Tumbled Chalcedony

Quartz (Silicon Dioxide - SiO2)

Tumbled chalcedony (likely yellow/brown agate or carnelian)

Microcrystalline quartz, SiO₂; chalcedony with possible iron-oxide staining

Polished brecciated jasper

Jasper, microcrystalline quartz (SiO₂), with iron-oxide and silica vein infill

Polished banded agate (likely carnelian and black agate)

Chalcedony, microcrystalline quartz (SiO₂), with iron-oxide coloration

Tumbled yellow chalcedony (likely honey agate or yellow quartz)

Microcrystalline quartz, SiO₂; coloration likely from iron oxides or included minerals

Tumbled jasper (likely picture/brecciated jasper)

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

Polished brown agate (likely carnelian/chalcedony)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide coloration

Blue chalcedony cabochon (likely dyed)

Microcrystalline quartz, SiO₂ (chalcedony)

Polished agate (likely moss or plume agate)

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

Tumbled banded agate

Microcrystalline quartz (chalcedony), SiO₂, with layered impurities

Jasper (likely brecciated jasper)

Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides

Banded Agate (Dyed Purple)

Agate (Variety of Chalcedony/Quartz), SiO2

Quartz (Microcrystalline variety)

Silicon Dioxide (SiO2)

Jasper with Quartz Veins

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Tumbled brown chalcedony (likely jasper or agate)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide staining

Agate

Chalcedony (Cryptocrystalline variety of Quartz, SiO2)

Red jasper (probable)

Microcrystalline quartz/chalcedony (SiO₂) colored by iron oxides

Jasper (specifically Yellow or Picture Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Blue Agate (Dyed)

Silicon Dioxide (SiO2) - Variety of Chalcedony

Tumbled agate/chalcedony pebble

Microcrystalline quartz (SiO₂), likely agate or jasper variety

Geode

Quartz / Chalcedony nodule

Agate (Geode nodule fragment)

Chalcedony (cryptocrystalline variety of Quartz), SiO2

Tumbled jasper and agate

Microcrystalline quartz (SiO₂), likely jasper/chalcedony; exact varieties cannot be confirmed from the image

Agate in Matrix

Silicon Dioxide (SiO2) within host rock

Chrysoprase

Nickel-bearing Chalcedony (SiO2 with inclusions of Ni-compounds like kerolite or pimelite)

Tumbled blue chalcedony/agate (likely glassy silica material)

Microcrystalline quartz, SiO₂; possibly blue chalcedony or dyed agate