Chert (Flint)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Chert (Flint)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement) SiO2
Chert Pebble
Chert (composed primarily of Microcrystalline Quartz, SiO2)
Chert (Jasper/Quartzite variety)
Microcrystalline Silica (SiO2)
Jasper
Silicon Dioxide (SiO2), microcrystalline quartz
Red Jasper
Silicon Dioxide with iron impurities (Quartz variety, SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz (Milky or Yellow/Citrine Quartz)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2)
Fossilized Chiton (Polyplacophora)
Polyplacophora (fossilized valves)
Amber
Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)
Petrified Wood
Silicified Wood (SiO2)
Imperial Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz with Mineral Inclusions
Petrified Wood and Mixed Rocks
Silicified Wood (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Amber
Succinite (a fossilized organic resin containing succinic acid)
Honey Calcite
Calcite (Calcium Carbonate, CaCO3)
Petrified Wood
Silicified Wood (primarily SiO2)
Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Red Sandstone
Arenite (Ferruginous Sandstone)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Chert (with Limestone/Marble traces)
Silicon Dioxide (SiO2) / Microcrystalline Quartz
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with fossil inclusions
Travertine / Tufa
Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Chert (Iron-stained)
Chert (SiO2)
Chert (and Limestone)
Silicon Dioxide (SiO2)
Rhodonite
Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3
Limestone ( weathered ) / Chert Nodular Rock
Sedimentary rock (primarily Calcium Carbonate, CaCO3, with Microcrystalline Quartz, SiO2)
Chert (Jasper/Agate variety)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Chert (River Pebble)
Microcrystalline quartz (SiO2)
Fossiliferous Limestone
Fossiliferous Carbonate Rock (CaCO3)
Fossilized Shark Tooth
Chondrichthyes tooth
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony replacing $SiO_2$)
Chert (Brown Chert / Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)