Chert (specifically Flint or Common Opal/Chalcedony mix)
Microcrystalline Quartz (SiO2)
sedimentary
Category
The Purple Specimen Is A Mineral (Amethyst); The White Specimen Is A Sedimentary Rock (Limestone Or Marble).
Browse the purple specimen is a mineral (amethyst); the white specimen is a sedimentary rock (limestone or marble). specimens identified by the Rock Identifier community.
Amethyst and Citrine (Ametrine Mix)
Silicon Dioxide (SiO2) with Fe3+ impurities
mineral
Sandstone (likely Fossiliferous)
Arenite / Sedimentum arenaceum
sedimentary
Sandstone with Manganese Dendrites/Oxide coatings
Arenite with Pyrolusite and Romanechite (MnO2)
sedimentary
Yellow Quartz
Silicon Dioxide (SiO2)
mineral
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Sedimentary or Metamorphic
Honey Calcite (Orange Onyx)
Calcium Carbonate (CaCO3)
mineral
Quartz Druzy on Agate (River Cobble)
Silicon Dioxide (SiO2)
Mineral / Sedimentary (often associated with volcanic hosts)
Orca Agate (Chalcedony)
Silicon Dioxide (SiO2) with inclusions
mineral
Gastropod Steinkern (Internal Mold Fossil)
Gastropoda (Class); Internal mold or 'Steinkern' composed of Calcium Carbonate (CaCO3) or Sedimentary matrix
sedimentary
Quartz (Milky or Clear variety)
Silicon Dioxide (SiO2)
mineral
Brecciated Jasper
Silicon Dioxide (SiO2) with varying mineral inclusions (Iron Oxide, Hematite, Clay)
sedimentary (clastic/chemical)
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Chert (and Chalcedony)
Silicon Dioxide (SiO2)
sedimentary
Sandstone (likely Ferruginous)
Arenite (SiO2 with iron oxide impurities)
sedimentary
Limestone (Ocherous)
Calcium Carbonate (CaCO3) with Iron Oxide (Limonite)
sedimentary
Citrine
Quartz (Silicon Dioxide - SiO2)
mineral
Yellow Quartz (Citrine Quartz)
Silicon Dioxide (SiO2)
mineral
Sandstone (Quartz-rich)
Arenite (composed primarily of SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite (Fe-rich)
sedimentary
Jasper with Agate Inclusions
Jasper (Silicon Dioxide, SiO2) with Chalcedony/Agate
sedimentary
Jasper or Chert with Quartz Vugs
Silicon Dioxide (SiO2)
sedimentary
Banded Chert
Cryptocrystalline Quartz (SiO2)
sedimentary
Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (with Quartz/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Fluorite
Calcium Fluoride (CaF2)
mineral
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
mineral
Quartz Vein in Host Rock (Pebble)
Quartz (SiO2) with sandstone or siltstone matrix
metamorphic/igneous transition
Chert (Brown variety)
Silicon Dioxide (SiO2)
sedimentary
Celestite (Celestine)
Strontium Sulfate (SrSO4)
mineral
Sandstone (Water-worn Pebble)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Chert (Chalcedony/Agate)
Microcrystalline Quartz (SiO2)
sedimentary
Stichtite in Serpentine (Atlantasite)
Mg6Cr2CO3(OH)16·4H2O in Mg3Si2O5(OH)4
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Quartz
Silicon dioxide (SiO2)
Mineral
Chert with Quartz/Calcite Vein
Microcrystalline Silica (SiO2)
sedimentary
Dendritic Agate
Dendritic Agate (Silicon Dioxide with Manganese or Iron Oxide inclusions, SiO2)
mineral
Banded Agate (Tumbled)
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Lapis Lazuli
Lapis Lazuli (A metamorphic rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, along with Calcite and Pyrite)
metamorphic
Agate (specifically Chalcedony nodule)
Silicon Dioxide (SiO2)
mineral
Sandstone (Weathered Pebble)
Arenite (composed primarily of SiO2)
sedimentary