Category
Browse sedimentary rock (possibly composed of various minerals) specimens identified by the Rock Identifier community.
Mixed Chalcedony and Jasper Bracelet (possibly 'Ocean Jasper' or similar banded variety for brown beads, and blue/grey Chalcedony for the translucent beads)
Chalcedony (SiO2), Jasper (SiO2 with impurities)
Sandstone
Arenite (composed primarily of SiO2)
Sandstone (likely Arkose)
Arenite (composed mainly of SiO2 with Feldspar)
Milky Quartz
Silicon Dioxide (SiO2)
Granite (Weathered)
Phaneritic Felsic Igneous Rock
Sandstone (Iron-stained)
Clastic sedimentary rock (SiO2 with Fe2O3 staining)
Granular Sandstone
Arenite (variable composition, primarily SiO2)
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Weathered Volcanic Rock (possibly Rhyolite or Andesite Pebble)
Volcanic rock (e.g., Rhyolite or Andesite, specific identification would require thin section analysis or chemical assay). Mineral composition: Primarily feldspars (orthoclase and/or plagioclase), quartz (in rhyolite), micas, amphiboles, and sometimes pyroxenes.
Conglomerate
Conglomerate (clastic sedimentary rock)
Sandstone (Weathered Coastal Boulder)
Arenite (composed primarily of SiO2)
Olivine in Basalt (Peridotite Xenolith)
Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt
Puddingstone
Conglomerate (specifically a type of jasper conglomerate or quartz conglomerate)
Moonstone
Adularia or Orthoclase (KAlSi3O8) or Albite (NaAlSi3O8), specifically with lamellar exsolution of albite and orthoclase.
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz with Fe2O3 staining)
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Jasper)
Biotite Schist (likely)
Biotite Schist (rock), Biotite (mineral)
Quartz
Silicon Dioxide (SiO2)
Quartz (likely)
Quartz (SiO2 - Silicon Dioxide)
Mookaite Jasper
Silicon Dioxide (SiO2) - Radiolarite
Quartz (likely macrocrystalline variety)
Quartz (SiO₂)
Chalcedony
Silicon Dioxide (SiO2)
Serpentinite
Serpentinite (a rock composed predominantly of serpentine group minerals)
Desert Rose
Gypsum (CaSO4·2H2O) or Baryte (BaSO4) with trapped sand grains
Sandstone (Wonderstone)
Arenite (composed primarily of SiO2 with Fe2O3 impurities)
Bumblebee Jasper (technically Bumblebee Stone)
Calcite, Aragonite, and Realgar/Orpiment mixture (SiO2 + CaCO3 + As2S3/As2S2)
Sandstone (Ferruginous)
Arenite with Iron-oxide inclusions (SiO2 primarily)
Sandstone
Arenite
Sandstone
Arenite (primarily SiO2)
Sandstone
Clastic Sedimentary Rock (composed of SiO2 grains)
Sandstone
Arenite
Granite and Igneous Mix
Phaneritic Felsic to Mafic Intrusive Rocks
Shale
Fissile mudrock (composed of clay-sized particles and detrital grains)
Fossil Shell Fragment (possibly Brachiopod or Bivalve)
Calcium Carbonate (CaCO3) - Phylum Brachiopoda or Mollusca
Diorite
Intrusive Igneous Rock (Intermediate Composition)
Massive Quartz (Milky or Gray)
Silicon Dioxide (SiO2)
Sandstone (likely Arkosic)
Clastic Sedimentary Rock (primarily SiO2 with Feldspar)
Quartz Vein in Host Rock
Quartz (SiO2) in Mafic or Sedimentary Matrix
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement
Quartz in Matrix (possibly Basalt or Siltstone host)
Silicon Dioxide (SiO2) in Host Rock
Sandstone
Arenite (composed primarily of SiO2)
Blue Chalcedony (Tumbled)
Silicon Dioxide (SiO2)
