Amethyst
Amethyst (Silicon Dioxide, SiO2)
Category
Browse sedimentary (volcanic) specimens identified by the Rock Identifier community.
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Amethyst
Silicon Dioxide (SiO2) with Iron impurities
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Obsidian
Obsidian (principally SiO2 + MgO, Fe3O4)
Basalt
Basalt (composition predominately Plagioclase feldspar and Pyroxene)
Jasper Agate
Silicon dioxide (SiO2)
Porphyritic Basalt
Porphyritic Mafic Extrusive Rock
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Hematite/Limonite inclusions
Gold Nugget
Native Gold (Au)
Basalt (Vesicular/Amygdaloidal or Water-Worn)
Basalt
Olivine (Peridot in gem form)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Quartz (Milky/Opaque variety)
Silicon Dioxide (SiO2)
Diabase (Greenstone)
Diabase (also known as Dolerite)
Amethyst (Rough)
Silicon Dioxide with iron impurities (SiO2)
Porphyry
Porphyritic Rhyolite or Andesite
Carnelian (Red Chalcedony)
SiO2 (Silicon Dioxide with Iron Oxide impurities)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Banded Agate (Lace Agate)
Agate (Variety of Cryptocrystalline Quartz), SiO2
Vesicular Basalt with Oxidation
Scoriaceous Olivine Basalt (Mafic volcanic rock)
Basalt (Vesicular)
Mafic Volcanic Rock (rich in Magnesium and Iron)
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Banded Agate (Yellow Agate)
Silicon Dioxide (SiO2)
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Basalt (Crushed Stone Aggregate)
Mafic Volcanic Basalt (Major Minerals: Plagioclase Feldspar, Pyroxene, Olivine)
Chert (Flint)
Silicon Dioxide (SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone
Arenite (SiO2 primarily)
Fossil Bivalve Shell
Class Bivalvia (e.g., Veneriidae family)
Sandstone (Ferruginous)
Arenite (with Iron Oxide)
Sandstone (Quartzose type)
Arenite (primarily SiO2)
Sandstone
Arenite (composed mainly of SiO2)
Sandstone (Ferruginous)
Arenite (Fe-rich)
Sandstone (likely Quartzose Sandstone with mineral staining)
Arenite (composed mainly of SiO2)
Reddish Brown Claystone or Siltstone
Argillite / Siltstone / Claystone
Sandstone (Micaceous)
Arenite (primarily SiO2 with Phyllosilicates)
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
Sandstone (Red)
Arenite (Fe2O3 heavy)
Sandstone
Arenite (SiO2 based)
Sandstone (Painted)
Arenite (primarily SiO2)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)