Microcrystalline Quartz

Tumbled brown jasper

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

Polished red jasper

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

Red-and-green jasper

Jasper, microcrystalline quartz (SiO₂), colored mainly by iron oxides and possibly chlorite/epidote

Red jasper

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

Tumbled red jasper (probable)

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

Polished jasper, likely ocean jasper or brecciated jasper

Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides and other inclusions

Agatized Coral (Petrified Coral)

Agatized Fossil Coral (Silicon Dioxide, SiO2 replacement after Anthozoa)

Chalcedony Agate / Carnelian nodules in Matrix

SiO2 (Silicon Dioxide) with iron oxide inclusions

Tumbled jasper

Microcrystalline quartz (SiO₂), commonly iron-rich jasper

Polished ocean jasper (orbicular jasper)

Microcrystalline quartz (SiO₂) with chalcedony, iron oxides, and assorted silicate inclusions

Likely tumbled jasper or iron-rich chert

Microcrystalline quartz (SiO₂), potentially hematite/goethite-bearing

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Red jasper with druzy quartz

Jasper (microcrystalline quartz, SiO₂), locally coated or veined with crystalline quartz

Rounded brown pebble

Likely iron-stained quartzite or chert; exact identification is uncertain from the photograph

Tumbled red jasper (probable)

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

Honey-colored chert or flint fragment

Microcrystalline quartz (SiO₂), likely chalcedony-rich chert

Polished jasper pebble

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

Tumbled jasper, likely picture or brecciated jasper

Microcrystalline quartz (SiO₂) with iron-oxide and other mineral impurities

Tumbled red jasper

Jasper, microcrystalline quartz (SiO₂) colored by iron oxides

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Tumbled chalcedony (likely carnelian or common agate)

Microcrystalline quartz, SiO₂; chalcedony variety

Weathered flint or chert fragment

Microcrystalline quartz (SiO₂), likely chert/flint

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Tumbled quartz-rich pebble, possibly chert or jasper

Microcrystalline quartz (SiO₂), likely chert/jasper; exact identification requires testing

Reddish-brown stone, possibly jasper

Likely iron-oxide-stained microcrystalline quartz (SiO₂); exact identification is uncertain from the image

Fancy Jasper

Silicon Dioxide (SiO2) with mineral inclusions

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Dyed Purple Agate

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Jasper

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Fossilized Coral (Rugose or Tabulate Coral)

Phylum Cnidaria, Class Anthozoa (silicified or calcified coral fossil)

Polished leopard-skin jasper (likely feldspar-rich decorative stone)

Trade name: leopard-skin jasper; appearance may also fit a feldspar-rich rock such as larvikite or gabbro

Tumbled reddish-brown chalcedony, possibly carnelian

Chalcedony (microcrystalline quartz), SiO₂; red variety commonly called carnelian

Tumbled brown chalcedony (possibly carnelian or agate)

Microcrystalline quartz, SiO₂; exact variety cannot be confirmed from the photo

Red jasper (probable iron-rich chert)

Jasper, microcrystalline quartz (SiO₂) colored chiefly by hematite/goethite

Tumbled agate and jasper specimens

Chalcedony (microcrystalline quartz, SiO₂), including agate and jasper varieties

Jasper and Basalt (Mixed Breccia or Chert)

Silicon Dioxide (SiO2) with Ferromagnesian silicates

Agate

Banded Chalcedony (SiO2 - Silicon Dioxide)

Quartz / Common Opal Transition

Silicon Dioxide (SiO2)

Tumbled yellow chalcedony (likely yellow jasper or quartz)

Microcrystalline quartz, SiO₂; probable chalcedony/jasper variety

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Jasper with Quartz Veining

Microcrystalline quartz (SiO2) with iron oxide impurities

Likely red jasper or iron-rich chert

Microcrystalline quartz (SiO₂) colored by hematite/goethite