Weathered volcanic rock, likely basalt
Basalt; commonly composed of plagioclase, pyroxene, and iron-rich oxides
igneous
Category
Man Made Material, Not A Natural Rock Or Mineral Specimen
Browse man made material, not a natural rock or mineral specimen specimens identified by the Rock Identifier community.
Learn about Man Made Material, Not A Natural Rock Or Mineral Specimen in the encyclopedia
View all →
Carnelian (red chalcedony), possibly red agate or jasper
Chalcedony, a microcrystalline variety of quartz; silicon dioxide (SiO₂), commonly colored red-orange by iron oxides. The specimen may include opaque jasper or agate zones.
gemstone
Milky Quartz Pebble with Iron Inclusions
Silicon Dioxide (SiO2)
mineral
Breciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite
Metamorphic Rock (composed primarily of Quartz, SiO2)
metamorphic
Polished/tumbled jasper, likely ocean jasper or brecciated jasper
Jasper: microcrystalline quartz (SiO₂) with iron oxides and other silicate impurities
mineral
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
gemstone
Prasiolite and Quartz Crystal Cluster
Quartz (SiO2); Prasiolite is a variety of Quartz
mineral
Citrine Quartz (likely heat-treated)
Silicon Dioxide (SiO2)
mineral
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
mineral
Quartzite Cobble
Quartzite (primarily SiO2)
metamorphic
Shale or Slate with Quartz Veins
Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins
Metamorphic, likely Sedimentary with Quartz veins
Chert (Siltstone / Flint)
SiO2 (Cryptocrystalline Quartz)
sedimentary
Chert (specifically Flint or Nodular Chert)
Silicon dioxide (SiO2)
sedimentary
Quartz (Herkimer Diamond variant)
Silicon Dioxide (SiO2)
mineral
Diorite (River Cobble)
Intermediate plutonic igneous rock
igneous
Quartzite Arrowhead (Archaeological Lithic)
Recrystallized Quartz (SiO2)
metamorphic
Quartz
Silicon Dioxide (SiO2)
mineral
Weathered chert or flint nodule
Microcrystalline quartz (SiO₂), commonly with chalcedony and minor iron oxides
sedimentary
Flower Jasper
Agatized Fossil Coral / Chalcedony (SiO2)
sedimentary
Biotite on Matrix
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
mineral
Dyed Howlite (often sold as Turquenite)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Basalt
Africite (Mafic Igneous Rock)
igneous
Sandstone
Sandstone (composed primarily of sand-sized minerals or rock grains)
sedimentary
River Siltstone Pebble
Siltstone (primarily composed of silica and clay minerals)
sedimentary
Jasper River Stone
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (Common Opal/Agatized Rock)
Microcrystalline Quartz (SiO2) with potential Chalcedony/Opaline silica
sedimentary
Citrine
Quartz (SiO2) - variety Citrine
Mineral
Sand
Siliciclastic sediment / Quartz sand (SiO2)
sedimentary
Yellow Quartz
Silicon Dioxide (SiO2)
mineral
Fossiliferous Limestone
Calcium Carbonate (CaCO3)
sedimentary
Diamond (in jewelry setting)
Carbon (C)
mineral
Gneiss (Metamorphic Pebble)
Gneissic Metamorphic Rock
metamorphic
Petrified Wood
Silicified Wood (primarily SiO2)
mineral
Ironstone Matrix with Jasper / Chert
Ferruginous Chert / Limonitic Jasper (SiO2 with Fe-oxides)
sedimentary
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
igneous
Black Beach Pebble / Basalt Pebble
Basalt / Mafic Volcanic Rock
igneous
Chert (specifically Flint or Dark Chalcedony)
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood (Silicified Wood)
Silicified Wood / Silicon Dioxide (SiO2)
metamorphic
Smoky Quartz
Smoky Quartz (SiO2)
mineral