Sedimentary (Chemically Precipitated)

Chert (Jasper / Petrified Wood)

Microcrystalline Quartz (SiO2)

Jasper with Quartz Druzy

Silicon Dioxide (SiO2)

Chert on Volcanic Host Rock

Sedimentary Chert (SiO2) within Basalt or Andesite

Moqui Marble (Sandstone Concretion)

Hematite-cemented Sandstone (Fe2O3 + SiO2)

Septarian Nodule

Septarian Concretion (CaCO3 with Siderite/Calcite)

Chalcedony (Agate / Quartz Geode Fragment)

Silicon Dioxide (SiO2)

Weathered iron-rich concretion or laterite fragment

Ferruginous concretion, likely goethite/limonite (hydrated iron oxides) in a clay-rich matrix

Jasper with Hematite

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3)

Microcrystalline Limestone

Limestone (CaCO3 with impurities)

Ocean Jasper

Orbicular Jasper (Silicon Dioxide, SiO2)

Banded Chert

Chert (Silicon Dioxide, SiO2)

Red calcite

Calcite (CaCO₃), likely iron- or manganese-colored

Quartz and Mixed Sedimentary Rocks

Silicon Dioxide (SiO2) mixed with various clastic sedimentary lithologies

Quartz / Common Opal Transition

Silicon Dioxide (SiO2)

Polished blue calcite

Calcite (CaCO₃), likely blue banded or massive calcite

Dolomite on Prehnite (Saddle-shaped Dolomite)

Dolomite [CaMg(CO3)2] on Prehnite [Ca2Al(AlSi3O10)(OH)2]

Hematite

Iron(III) oxide (Fe2O3)

Limestone with Calcite Crystals

Sedimentary Rock containing Calcium Carbonate (CaCO3)

Yellow Ochre / Limonite

Limonite (FeO(OH)·nH2O)

Honey calcite (orange calcite)

Calcite, calcium carbonate (CaCO₃)

Jasper

Microcrystalline Quartz (SiO2)

Moqui Marbles

Ironstone Concretions (Hematite / Goethite / Sandstone)

Fossiliferous Limestone with Rugose Coral

Calcite (CaCO3) containing a Rugosa (Horn Coral) fossil

Ferruginous Sandstone

Arenite with limonite/goethite cement

Fossiliferous Limestone with Brachiopod

Limestone (Calcium Carbonate, CaCO3) with Phylum Brachiopoda fossil

Ocean Jasper

Orbicular Jasper (Silicon Dioxide SiO2)

Limestone Pebble

Calcite-rich Sedimentary Rock (CaCO3)

Red Jasper

Microcrystalline Quartz (SiO2)

Chert Nodule in Limestone (Flint in Chalk)

SiO2 (Microcrystalline Quartz) in CaCO3 (Calcite)

Moqui Marble (Shaman Stone)

Ironstone Concretion (Goethite/Hematite Shell)

Sandstone (Ferruginous)

Arenite (Fe-rich SiO2)

Banded Calcite (Mexican Onyx)

Calcium Carbonate (CaCO3)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Tumbled yellow calcite

Calcite (CaCO₃), likely honey/yellow calcite

Quartz Geode

Silicon Dioxide (SiO2) in Geode form

Tufa

Calcareous Tufa (CaCO3)

Jasper pebble (possibly Red Jasper or Lake Superior Agate/Jasper mix)

Silicon Dioxide (SiO2) with Hematite inclusions

Red Jasper

Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)

Jasper with Quartz inclusion

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Celadonite in Basalt (Green Earth)

Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)

Orange Calcite

Calcium Carbonate (CaCO3)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions