Agate
Silicon dioxide (SiO2)
mineral
Category
Not A Rock (Man Made Origin)
Browse not a rock (man made origin) specimens identified by the Rock Identifier community.
Quartz on Greenstone
Silicon Dioxide (SiO2) on Altered Igneous Geologic Unit
metamorphic
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
mineral
Rose Quartz
Silicon Dioxide (SiO2)
mineral
Jasper with Quartz inclusions
Silicon Dioxide (SiO2) with impurities
sedimentary
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz
sedimentary
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
Mixed Tumbled Gemstones and River Rocks
Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)
Mixed (Igneous, Sedimentary, Metamorphic, and Minerals)
Scoria (with likely iron oxidation)
Scoria (Basaltic Scoria)
igneous
River Pebbles and Quartz
Mixed Igneous, Sedimentary, and Metamorphic Rocks (Silicon Dioxide SiO2 dominant)
mixed
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
metamorphic
Quartzite Pebble (River Rock)
Quartzite (mainly SiO2)
metamorphic
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
sedimentary
Sandstone (Quartzose Sandstone)
Clastic Terrigenous Sedimentary Rock (primarily SiO2)
sedimentary
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
igneous
Granite Cobble
Plutonic Igneous Rock (Granitic)
igneous
Jasper (Yellow/Brown variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Sandstone
Arenite
sedimentary
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Yellow Jasper
Silicon Dioxide (SiO2) - Impure Cryptocrystalline Quartz
sedimentary
Sandstone (clastic)
Clastic Sedimentary Rock (primarily composed of SiO2)
sedimentary
Vesicular Basalt (or Scoria)
Vesicular Basalt
igneous
Basalt Scoria
Vesicular Basalt
igneous
Moss Agate
Silicon Dioxide (SiO2) with inclusions
mineral
Quartz (Milky/Common Quartz)
Silicon Dioxide (SiO2)
mineral
Agate Geode / Nodular Chalcedony
Silicon Dioxide (SiO2) with impurities
mineral
Gastropod Steinkern (Internal Mold Fossil)
Gastropoda (Class); Internal mold or 'Steinkern' composed of Calcium Carbonate (CaCO3) or Sedimentary matrix
sedimentary
Jasper
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary
Chert (Common Opal/Agate mixture)
Microcrystalline Quartz (SiO2)
sedimentary
Tiger's Eye (Rough)
Pseudomorph of Quartz after Crocidolite (SiO2)
mineral
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Sandstone
Arenite (SiO2 primarily)
sedimentary
Granitic Pegmatite
Coarse-grained Igneous Rock (Granitic composition: KAlSi3O8, SiO2)
igneous
Quartzite with Iron Inclusions
Metamorphic Quartzite (SiO2 with Fe2O3 trace impurities)
metamorphic
Sandstone (likely Quartzose Sandstone)
Arenite (SiO2 predominantly)
sedimentary
Mudstone
Lutylite (group of fine-grained sedimentary rocks)
sedimentary
Eclogite
Eclogite (Pyrope garnet and Omphacite pyroxene)
metamorphic
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
sedimentary
Ocherous Sandstone (Ferruginous Sandstone)
Ferruginous Arenite (SiO2 with Fe2O3)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2) within a geode
sedimentary
Sandstone
Arenite (primarily SiO2 - Silicon Dioxide)
sedimentary
Stream Pebble (Basalt/Greywacke)
Mafic Igneous Rock (Fine-grained)
igneous