Basalt (tumbled/river-worn)
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Category
Browse not a natural rock specimens identified by the Rock Identifier community.
Basalt (tumbled/river-worn)
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Basalt (River Stone)
Basalt
Schist (Garnet-Mica Schist)
Garnet-Mica Schist
Basalt
Basalt (composition of plagioclase feldspar and pyroxene)
Basalt with Plagioclase Microphenocrysts
Amygdaloidal or Porphyritic Basalt
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt (River Stone)
Basalt
Granite
Phaneritic plutonic felsic rock (primarily Quartz, Feldspar, and Mica)
Basalt
Basalt (primarily composed of Plagioclase Feldspar and Pyroxene)
Basalt River Stone
Basalt (Aphanitic Mafic Igneous Rock)
Basalt (Weathered)
Extrusive Igneous Rock (Mafic composition)
Lake Superior Agate
Cryptocrystalline Quartz (SiO2)
Dalmation Stone (often called Dalmatian Jasper)
Peralkaline Rock (Microgranite/Aplite), SiO2 with inclusions of Arfvedsonite
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Sandstone
Arenite (SiO2 primarily)
Basalt Beach Pebble
Basalt (Aphanitic Mafic Igneous Rock)
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
River Stone (Basalt)
Basalt (Aphanitic Mafic Igneous Rock)
Basalt
Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
Unakite
Epidotized Granite
Granite
Granite (compositionally of Quartz, Alkali Feldspar, and Plagioclase)
Druzy Quartz
Silicon Dioxide (SiO2)
Calligraphy Stone
Mariam Jasper (Fossiliferous Limestone with Hematite and Iron)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Sandstone (Picture Sandstone)
Arenite (primarily SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2)
Snowflake Obsidian
Obsidian with Cristobalite inclusions (70–75% SiO2)
Yellow Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
River Pebble (Likely Quartzite or Chert)
Quartzite (primarily SiO2)
Obsidian
Volcanic Glass (70-75% SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)
Red Jasper with Quartz Veining
Jasper (Silicon Dioxide, SiO2) with Quartz (SiO2) inclusions
Jasper (Iron-stained Quartzite/Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Snowflake Obsidian
Volcanic glass with Spherulite inclusions (SiO2)
Yellow Quartzite (River Pebble)
Quartzite (primarily SiO2 with iron oxide inclusions)
Sandstone
Arenite (often composed of Quartz, SiO2)
Moss Agate
Chalcedony (Silicon Dioxide / SiO2)
Rose Quartz
Silicon Dioxide (SiO2)