Diorite (possibly fine-grained variety or a related intermediate intrusive rock like a felsic gabbro or a dark granodiorite)
Diorite (Igneous rock, intrusive, intermediate composition)
Igneous Rock
Category
Sedimentary Rock (Technically A Microcrystalline Quartz Mineral Aggregate)
Browse sedimentary rock (technically a microcrystalline quartz mineral aggregate) specimens identified by the Rock Identifier community.
Coarse-grained Quartz with Feldspar inclusions
Crystalline Quartz (SiO2) with Orthoclase/Plagioclase Feldspar inclusions
igneous
Agate
Agate (Silicon Dioxide - SiO2)
mineral
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Sandstone (Quartz Arenite)
Clastic Sedimentary Rock - Quartz Arenite
sedimentary
Yellow Quartz (Citrine/Yellow Jasper mix)
Silicon Dioxide (SiO2)
mineral
Granite Cobble
Granite (Phaneritic Igneous Rock)
igneous
Granite Gneiss
Gneiss (High-grade regional metamorphic rock)
Metamorphic
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Jasper and Basalt (Mixed Breccia or Chert)
Silicon Dioxide (SiO2) with Ferromagnesian silicates
sedimentary and igneous (mixed)
Polygenetic Breccia
Clastic Breccia (containing lithic fragments in a fine-grained matrix)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (primarily SiO2 with Fe2O3)
sedimentary
Quartz (Riverstone / Cobble)
Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite
sedimentary
Quartzite
Quartzite (primarily SiO2)
metamorphic
Yellow Jasper
Silicon Dioxide (SiO2)
sedimentary
River Pebbles (Tumbled Quartz and Basalt)
Silicon Dioxide (SiO2) for white quartz; Mafic Volcanic Rock for basalt
igneous and sedimentary
Quartz Druse (on Chalcedony/Agate base)
Silicon Dioxide (SiO2)
mineral
Chalcedony
Chalcedony (a microcrystalline variety of Quartz, SiO2)
Mineral
Quartz Geode (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
Sandstone (likely Greywacke variant)
Arenite
sedimentary
Jasper (Red Jasper with Quartz veins)
Jasper (Silicon Dioxide, SiO2)
sedimentary
Ferruginous Sandstone
Arenite with Iron-Oxide cement (Fe2O3 · nH2O)
sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Clear Quartz (Druzy)
Crystalline Silicon Dioxide (SiO2)
mineral
Tree Agate (or Moss Agate), faceted into a crystal tower
Dendritic Agate (Silicon Dioxide, SiO2)
Mineral
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
sedimentary
Limonitic Quartzite
Metamorphosed sandstone with Limonite (FeO(OH)·nH2O) staining
metamorphic
Green Apophyllite and Stilbite on Quartz Cluster
Apophyllite-(K) (KCa4(Si8O20)(F,OH)·8H2O), Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O), Quartz (SiO2)
Mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Geode (Quartz)
Silicon Dioxide (SiO2)
mineral
Coarse Sand Grain / Lithic Fragment
Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)
sedimentary
Granite
Granite (a common rock type, not a single mineral species)
Igneous
Quartz (Milky Quartz)
Silicon Dioxide (SiO₂)
mineral
Red Jasper
Microcrystalline quartz (SiO2) with Hematite (Fe2O3) impurities
sedimentary
Puddingstone (specifically Michigan/Gowganda Puddingstone)
Conglomerate (Jasper Conglomerate)
sedimentary
Granite Gneiss
High-grade regional metamorphic rock (Quartz-Feldspar Gneiss)
metamorphic
Sandstone Pebble (Quartzite-rich)
Clastic Terrigenous Sedimentary Rock (SiO2 dominant)
sedimentary
Red Jasper
Red Jasper (SiO2 with Fe2O3 impurities)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2) within a geode
sedimentary