Banded Agate (specifically Sardonyx)
Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz
mineral
Category
Industrial Byproduct (Anthropogenic Rock)
Browse industrial byproduct (anthropogenic rock) specimens identified by the Rock Identifier community.
Precious Opal
Hydrated Silica (SiO2·nH2O)
mineraloid
Quartzite
Quartzite (primarily SiO2)
metamorphic
Fulonite (Fulgurite-like)
Fulgurite (SiO2 fused silica/lechatelierite)
Metamorphic (Pseudo-igneous)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Coal (specifically Bituminous or Anthracite)
Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N
sedimentary
Greywacke (River Pebble)
Greywacke sandstone with quartz veining
sedimentary
Chert (often called Flint or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (Nodule)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Anthracite Coal
Anthracite (Carbon-rich metamorphic sedimentary rock)
sedimentary
Anthracite Coal
Anthracite (Carbon-rich Sedimentary-to-Metamorphic Rock)
metamorphic
Granitic Pegmatite Intrusion in Host Rock
Pegmatite dike in amphibolite or schist
igneous and metamorphic
Quartzite
Quartzite (SiO2 silicon dioxide)
metamorphic
Granite
Plutonic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
igneous
Milky Quartz (with Iron Oxide staining)
Quartz (Silicon Dioxide - SiO2)
mineral
Dumortierite Quartz (Blue Quartz)
Al7BO3(SiO4)3O3 (Aluminum Boro-silicate included in Quartz)
mineral
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide - SiO2)
mineral
Chert (specifically tan/pink variety)
Silicon Dioxide (SiO2)
sedimentary
Red Quartzite
Quartzite (SiO2 with iron oxide impurities)
metamorphic
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Quartzite
Quartzite (SiO2 silicon dioxide)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Granitic Pegmatite
Coarse-grained Granite (KAlSi3O8 + SiO2)
igneous
Bauxite
Alumina-rich rock (consisting of Gibbsite, Boehmite, and Diaspore)
sedimentary
Peridotite
Ultramafic intrusive igneous rock (composition: (Mg, Fe)2SiO4)
igneous
Chert (Quartz Pebble)
Silicon Dioxide (SiO2)
sedimentary
Bouncy Ball (Synthetic Rubber Polymer)
Polybutadiene / Ethylene Vinyl Acetate (EVA)
Synthetic material (Not a rock or mineral)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Unknown Organic Object (likely a berry or fruit)
Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.
Organic Material (likely a fruit or berry)
Schist
Mica Schist (primarily Muscovite and Quartz)
metamorphic
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Granite
Phaneritic intrusive igneous rock (Composition: Quartz, Feldspar, Mica)
igneous
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Banded Chert in Matrix
Microcrystalline Quartz (SiO2)
sedimentary
Milky Quartz
Quartz (SiO2) with iron staining
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Pink Quartzite
Quartzite (SiO2 with iron oxide inclusions)
metamorphic
Zinc Alloy (Silver-plated)
Zinc Alloy Casting (Zn-Al-Mg-Cu)
mineral (refined metal)
Banded Chert (River Pebble)
Microcrystalline Quartz (SiO2)
sedimentary