Gneiss
Gneiss
metamorphic
Category
Man Made Rock (Sedimentary Analogue)
Browse man made rock (sedimentary analogue) specimens identified by the Rock Identifier community.
Garnet Schist
Almandine-Garnet Mica Schist
metamorphic
Gneiss (River Cobble)
Gneiss (Foliated Metamorphic Rock)
metamorphic
Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Quartz Geode in Sedimentary Matrix
Silicon Dioxide (SiO2) within a limestone/dolostone host
mineral
Sea Glass (Teal/Turquoise)
Amorphous Silica (SiO2) with trace metal oxides
Anthropogenic (Man-made material processed by nature)
Sea Glass (Turquoise/Aqua)
Amorphous Silica (SiO2) with transition metal dopants
Anthropogenic (Man-made material processed by nature)
Bauxite (Laterite)
Hydrated aluminum oxides (Al2O3·nH2O)
sedimentary
Red Sandstone
Arenite with Iron Oxide (Hematite) cement
sedimentary
Bauxite
Bauxite (principal ore of aluminum, primarily Al(OH)3)
sedimentary
Red Sandstone
Arenite
sedimentary
Agate Geode
Silicon Dioxide (SiO2) - variety Chalcedony/Quartz
sedimentary
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Mineral or Sedimentary Rock (with mineral inclusions)
Quartzite Pebble (River Rock)
Quartzite (mainly SiO2)
metamorphic
Druzy Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (likely Rose Quartz or Milky Quartz based on color)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Quartz (likely) or a Quartzite Pebble
Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.
Mineral, specifically a detrital grain
Sandstone
Arenite (SiO2 primarily)
sedimentary
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz
sedimentary
Quartz Veinated Sandstone or Siltstone
Silicon Dioxide (SiO2) within a clastic sedimentary matrix
sedimentary
Sandstone
Arenite
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) - Impure Cryptocrystalline Quartz
sedimentary
Chert (Common Opal/Agate mixture)
Microcrystalline Quartz (SiO2)
sedimentary
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Quartz (Common Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Limonite Concretion
Limonite (Hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)
sedimentary
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Druzy Quartz Geode (likely Smokey Quartz variety)
Silicon Dioxide (SiO2) - specifically a geode formation lined with druzy quartz crystals, with a likely brownish hue indicating smokey quartz.
Mineral structure/Rock
Sandstone Concretion
Ferruginous Sandstone Concretion (SiO2 + FeO(OH))
sedimentary
Crinoid Fossil Marble
Crinoidal Limestone / Phylum Echinodermata
sedimentary
Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Sandstone Concretion
Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)
sedimentary
Gneiss
Metamorphic Rock (Gneissic texture)
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Jasper with Quartz inclusion
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Quartz
Quartz (SiO₂)
Mineral
Anthracite Coal
Anthracite (Carbon-rich Sedimentary-to-Metamorphic Rock)
metamorphic
Quartz on Schist
Silicon Dioxide (SiO2) on Foliated Metamorphic Rock
metamorphic