Ferruginous Sandstone
Arenite with Hematite/Limonite cement (SiO2 + Fe2O3)
sedimentary
Category
Sedimentary (Chemically Precipitated Mineral)
Browse sedimentary (chemically precipitated mineral) specimens identified by the Rock Identifier community.
Chert
Microcrystalline silica (SiO2)
sedimentary
Calcite
Calcium Carbonate (CaCO3)
mineral
Quartz
Silicon dioxide (SiO₂)
Mineral
Banded Chert (Flint/Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Porphyritic Andesite
Intermediate Volcanic Rock - Andesite
Igneous
Quartzite (Yellow/Iron-stained Quartz)
Quartzite (primarily SiO2 with iron oxide impurities)
metamorphic
Quartz / Quartzite Pebble
Silicon Dioxide (SiO2)
metamorphic
Yellow Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz (Riverstone / Cobble)
Silicon Dioxide (SiO2)
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Carnelian Agate
Silicon Dioxide (SiO2)
mineral
Quartz (Gravel Pebble)
Silicon Dioxide (SiO2)
mineral
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Banded Agate (specifically Botryoidal/Orbicular Agate)
Silicon Dioxide (SiO2)
Mineral (variety of Chalcedony/Quartz)
Chert (and Jasper/Chalcedony mixture)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Mineral
Rhodolite Garnet
Magnesium Aluminum Silicate; formula: (Mg,Fe)3Al2(SiO4)3
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
Mineral (occurring as a rolled clast)
Milky Quartz (Beach Pebble)
Quartz (Silicon Dioxide, SiO2)
mineral
Concretion or Geode (unbroken)
Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.
Sedimentary rock (specifically a concretion or possibly a geode)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxides (FeO(OH)·nH2O)
mineral
Chert (Iron-stained)
Chert (primarily Microcrystalline Quartz, SiO2)
sedimentary
Limestone (specifically Fossiliferous or Crinoidal Limestone)
Calcium Carbonate (CaCO3) - Calcite Rock
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Ferruginous Quartz (Carnelian-tinted Quartz)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Quartz (Water-worn pebble)
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Quartz (Silicon Dioxide - SiO2)
mineral
White Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Opalite
Synthetic Glass (Simulated Opal)
mineral
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Quartz (possibly milky quartz or quartz with inclusions)
SiO2 (Silicon Dioxide)
Mineral
Jasper Geode
Silicon Dioxide (SiO2) with impurities
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
Mineral
Chert (and Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
sedimentary
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary