Chert
Silicon dioxide (SiO2)
sedimentary
Category
Marble
Browse marble specimens identified by the Rock Identifier community.
Oolitic Limestone
Oolitic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Oolitic Limestone
Oolitic Carbonate (CaCO3)
sedimentary
Oolite (Ooids)
Oolitic Limestone (Principal mineral: Calcite, CaCO3)
sedimentary
Chert (Chert Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Black Limestone with Calcite Veining
Bituminous Limestone (CaCO3 with Organic Carbon inclusions)
sedimentary
Diamond
Diamond (pure Carbon, C)
mineral
Mookaite Jasper
Silicified Radiolarite (SiO2)
sedimentary
Chert (Iron-stained River Cobble)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Nodule)
Cryptocrystalline Silica (SiO2)
sedimentary
Chert (Hagstone/Gasket Rock variant)
Chert (SiO2)
sedimentary
Sandstone (Muddy/Silty Variety)
Arenite with high silt/clay content (clastic sedimentary rock)
sedimentary
Diamond
Cubic Carbon (C)
mineral
Chert Pebble / Brachiopod Fossil Internal Mold
Silicon Dioxide (SiO2) / Fossil: Brachiopoda (generic internal mold)
sedimentary
Milky Quartz in Conglomerate Matrix
Silicon Dioxide (SiO2) within Clastic Sedimentary Rock
sedimentary
Sandstone (Water-worn Pebble)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide staining/cementing)
sedimentary
Aragonite Star Cluster
Aragonite (Sputnik habit) - CaesarCO3
mineral
Red Siltstone (or Red Shale)
Clastic Sedimentary Rock (Composition: primarily Quartz, Clay minerals, and Hematite Fe2O3)
sedimentary
Chert (Arrowhead or Projectile Point)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Banded Iron Formation (BIF) with Quartz
Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)
Sedimentary
Red Sandstone
Arenite (primarily Quartz and Feldspar with Iron Oxide cement)
sedimentary
Diamond
Diamond (Carbon, C)
Mineral
Himalayan Salt
Halite (mineral name), chemical formula NaCl (sodium chloride). Generally, 'Himalayan Salt' is a trade name for evaporite minerals from specific regions.
Mineral
Olivine (likely Peridot variety)
Olivine Mineral Group (specifically Forsterite-Fayalite solid solution series); Chemical formula: (Mg,Fe)2SiO4
Mineral
Diamond
Diamond (C)
Mineral
Diamond
Diamond (C)
Mineral
Diamond
Diamond (C)
Mineral
Diamond
Diamond (a metastable allotrope of carbon, C)
Mineral
Diamond
Diamond (C)
Mineral
Chert (Jasper-like)
SiO2 (Cryptocrystalline Quartz)
Sedimentary
Chert (Flint)
SiO2 (predominantly microcrystalline or cryptocrystalline quartz)
Sedimentary rock
Garnet (likely Pyrope or Almandine)
Garnet Group (complex nesosilicate minerals, e.g., Pyrope Mg3Al2(SiO4)3, Almandine Fe3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3, Grossular Ca3Al2(SiO4)3, Andradite Ca3Fe2(SiO4)3, Uvarovite Ca3Cr2(SiO4)3). The vivid red color in the image strongly suggests Pyrope or Almandine.
Mineral
Chert / Flint (a variety of Chert)
Chert (SiO2)
Sedimentary Rock (technically a microcrystalline quartz mineral aggregate)
Peridot
Olivine ((Mg,Fe)2SiO4)
Mineral
Chert (or Flint)
Chert (a cryptocrystalline variety of quartz, SiO2)
sedimentary
Chert
Chert (microcrystalline quartz, SiO2)
sedimentary
Peridot
Olivine (specifically, the gem-quality variety forsterite, (Mg,Fe)2SiO4)
Mineral
Howlite (Tumbled)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Chert / Flint
Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂
Mineral
Chert (varieties include Flint or Jasper)
Chert (cryptocrystalline quartz; SiO₂)
Sedimentary
Peridot (likely, based on color and appearance)
Olivine group mineral, specifically (Mg,Fe)2SiO4 (Forsterite-Fayalite solid solution series)
Mineral