Sedimentary Rock (Technically A Variety Of Chalcedony)

Amethyst or Smoky Quartz Geode Slice

Crystalline Silicon Dioxide (SiO2) with iron impurities

Chert or flint

Microcrystalline quartz (SiO₂), often chalcedony

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Red Jasper

Jasper (Silica with Hematite inclusions), SiO2

Polished brecciated jasper (likely ocean jasper or orbicular jasper)

Microcrystalline quartz/chalcedony (SiO₂) with iron-oxide and other mineral inclusions

Yellow Chalcedony (Carnelian/Yellow Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Jasper

Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)

Chert / Flint Nodule

Cryptocrystalline quartz (SiO2)

Thunder Egg (Agate/Jasper filled)

Chalcedony variety Agate/Jasper in a Rhyolitic matrix

Weathered quartz-rich pebble, possibly quartzite or chert

Quartz (SiO₂), possibly quartzite; exact identification is uncertain from the image

Jasper

Jasper (Silicon Dioxide, SiO2)

Jasper

Silicon dioxide, SiO2

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Polished brecciated jasper (likely septarian or iron-rich jasper)

Microcrystalline quartz (chalcedony), SiO₂, with iron oxides and possibly calcite or other rock fragments

Tumbled red jasper

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

Dendritic Agate

Silicon Dioxide with Manganese/Iron oxide inclusions (SiO2)

Dalmation Jasper (or Dalmation Stone)

Dalmation Stone (composed of Perthite, Quartz, and Arfvedsonite)

Tumbled carnelian or orange chalcedony

Chalcedony (microcrystalline quartz), SiO₂; likely iron-stained variety

Tumbled Black Stone

Unknown, possibly Obsidian, Onyx, or Tourmaline

Carnelian (a variety of Chalcedony)

Cryptocrystalline Quartz (SiO2) with iron oxide inclusions

Polished yellow jasper

Jasper, microcrystalline quartz (SiO₂), commonly containing iron oxides and other silicates

Yellow Jasper

Chalcedony (SiO2 with iron oxide inclusions)

Polished carnelian (likely)

Cryptocrystalline quartz, SiO₂; orange chalcedony, commonly called carnelian

Tumbled agate or chalcedony (probable)

Microcrystalline quartz, SiO₂

Jasper

Chalcedony (SiO2)

Red Jasper (Brecciated or Mottled)

Silicon Dioxide (SiO2) with iron oxide inclusions

Jasper

Silicon dioxide (SiO2)

Yellow jasper or iron-stained chert

Microcrystalline quartz (SiO₂), commonly colored by iron oxides

Black Onyx

Silicon dioxide (SiO2)

Jasper

Silicon dioxide (SiO2)

Orange carnelian (likely tumbled chalcedony)

Cryptocrystalline quartz, SiO₂; orange color commonly from iron oxides

Tumbled jasper or iron-rich chert

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

Jasper with Quartz inclusions

Silicon Dioxide (SiO2) with impurities

Jasper (Yellow/Brown variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Jasper (likely Brecciated or Multi-colored)

Jasper (SiO2)

Chert

Microcrystalline or cryptocrystalline quartz (SiO2)

Agate (Common Chalcedony)

Silicon Dioxide (SiO2)

Quartz (Agate/Chalcedony)

Silicon Dioxide (SiO2)

Aggregate Concrete

Anthropogenic Conglomerate (Technosol)

Yellow Jasper

Silicon Dioxide (SiO2) with Goethite/Iron inclusions

Polished banded agate

Microcrystalline quartz (SiO₂), chiefly chalcedony

Tree Agate

Silicon Dioxide (SiO2) with Chlorite inclusions