Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
Category
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.
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
Belemnoit (Fossil)
Belemnoidea (Order), Rostrum / Guard
Quartz Pebble
Silicon Dioxide (SiO2)
Dream Amethyst (Chevron Amethyst)
Silicon Dioxide (SiO2) with iron impurities
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Quartz (variety of colors)
SiO2 (Silicon Dioxide)
Sandstone (Quartzose type)
Arenite (primarily SiO2)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Peacock Ore (Chalcopyrite)
Chalcopyrite (CuFeS2)
Quartz (likely Herkimer Diamond style)
Silicon Dioxide (SiO2)
Chert (Field Stone)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
Chert Pebble (Jasper variant)
Microcrystalline Quartz (SiO2)
Amethyst Quartz Druse
Silicon Dioxide (SiO2) with iron impurities
Yellow Calcite
Calcium Carbonate (CaCO3)
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (Lithic arenite / Quartz arenite)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Citrine
Silicon Dioxide (SiO2)
Sandstone (Quartzose Sandstone)
Arenite (SiO2 primarily)
Chert (Iron-stained)
Chert (Silicon Dioxide, SiO2)
Honey Calcite Geode Segment
Calcite (Calcium Carbonate, CaCO3)
Chalcedony (Agate/Carnelian precursor)
Chalcedony (Silicon Dioxide, SiO2)
Chalcedony Nodule (Commonly known as Agate or Chert)
Microcrystalline Quartz (SiO2)
Turquoise in Matrix
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Fossiliferous Limestone (Coquina / Shell Limestone)
CaCO3 (Calcium Carbonate)
Chalcedony (Botryoidal)
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Basalt with inclusion
Basalt (Aphanitic-Porphyritic texture)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Cobaltoan Calcite / Pink Dolomite (Possible)
Cobaltoan Calcite: (Ca,Co)CO3; Pink Dolomite (or Thulite): CaMg(CO3)2 or Mn-Dolomite / (Thulite: Mn2+3Al2(Si2O7)(SiO4)O(OH))
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
Yellow Quartz (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Sandstone (Pebble/Cobble)
Arenite (primarily SiO2)
Fossiliferous Limestone (Crinoidal)
Bioclastic Limestone (predominantly CaCO3)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Lapis Lazuli
Lapis Lazuli (a rock type, not a single mineral; main component is Lazurite (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)])
Echinoidea (Fossil Sea Urchin)
Echinodermata Echinoidea
Yellow Citrine Quartz
Silicon Dioxide (SiO₂)
Chert (with possible fossils)
Microcrystalline quartz (SiO2)
Chert (specifically Chalcedony/Flint variant)
Silicon Dioxide (SiO2)
Quartz (Milky/Smoky variety on matrix)
Silicon Dioxide (SiO2)