Sand Grain (Quartz)
Silicon Dioxide (SiO2)
sedimentary
Category
Mineralogical Specimen
Browse mineralogical specimen specimens identified by the Rock Identifier community.
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Optical Calcite
Calcium Carbonate (CaCO3)
mineral
Graphite Schist
C (Carbonaceous Schist)
metamorphic
Hag Stone
Sandstone or Limestone with Solution Holes (Bioturbation/Erosion)
sedimentary
Tumbled green aventurine (probable)
Quartz, SiO₂, with fuchsite mica inclusions
mineral
Tumbled kambaba jasper (likely)
Kambaba jasper, a silica-rich microcrystalline quartz aggregate, commonly containing fossilized cyanobacterial structures and dark green amphibole/pyroxene minerals
sedimentary
Limestone or Sandstone Cobble
Sedimentary rock (Calcium carbonate or Quartz based)
sedimentary
Sandstone Concretion
Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)
sedimentary
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
mineral
Dalmatian jasper
Orbicular microcrystalline quartz rock, commonly rhyolitic or volcanic-feldspar matrix with black arfvedsonite/alkali-amphibole inclusions
igneous
Painted Garden Rock
Coated Siltstone or Mudstone
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Diorite
Diorite (an intermediate intrusive igneous rock)
igneous
Schist (likely Mica Schist)
Mica Schist
metamorphic
Weathered iron-rich volcanic rock
Likely altered basalt or andesite with iron-oxide staining
igneous
Granite (Alkali-feldspar Granite)
Felsic Plutonic Rock (Primary minerals: Quartz SiO2, Orthoclase KAlSi3O8, Plagioclase (Na,Ca)AlSi3O8)
igneous
Pink Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Granite (with Orthoclase and Quartz)
Phaneritic Felsic Igneous Rock (KAlSi3O8 + SiO2)
igneous
Mixed River Pebbles
Clastic Sedimentary Alluvial Deposit / Polymictic Conglomerate Clasts
sedimentary
Eclogite
Eclogite (Omphacite + Almandine-Pyrope Garnet)
metamorphic
Granite Cobble
Plutonic Granite
igneous
River Pebbles (Stream-rounded rocks)
Fluvial Detritus (varied mineralogy)
Mixed (predominantly sedimentary and igneous)
Flint or chert flake
Microcrystalline quartz (SiO₂), commonly chert/flint
sedimentary
Greenstone / Glauconitic Siltstone
Metabasalt or Glauconite-rich Sedimentary Rock
metamorphic or sedimentary
Tumbled azurite–malachite or blue jasper (tentative)
Likely azurite-bearing copper mineral aggregate; composition commonly Cu₃(CO₃)₂(OH)₂ with associated malachite Cu₂CO₃(OH)₂
mineral
Pink Granite
Phaneritic Felsic Igneous Rock
igneous
Granite Pegmatite
Granitic Pegmatite (composition: SiO2 with KAlSi3O8)
igneous
Tumbled dark green stone, likely serpentine
Serpentinite; chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄)
metamorphic
Chert or flint nodule
Microcrystalline quartz (SiO₂), commonly chalcedony with possible opaline silica
sedimentary
Granodiorite
Granodiorite (containing Plagioclase, Quartz, and Biotite)
igneous
Granitic Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Granite
Phaneritic Plutonic Felsic Rock
igneous
Granite (Fine-grained)
Phaneritic Felsic Igneous Rock
igneous
Granite
Granite (Felsic Plutonic Rock)
igneous
Granite
Phaneritic Plutonic Igneous Rock (Granite)
igneous
Granite
Phaneritic Igneous Rock (composed of quartz, alkali feldspar, and plagioclase)
igneous
Granite
Felsic Intrusive Igneous Rock
igneous
Tumbled orange chalcedony and a gray stone disk
Chalcedony (microcrystalline quartz, SiO₂); disk likely fine-grained sandstone or slate
mineral
Greenstone / River Jadeite pebble
Metavolcanic rock / Chlorite or Actinolite-rich schist
metamorphic
Greenstone (Metabalt)
Chlorite-actinolite schist (Greenstone)
metamorphic
Green Obsidian Sphere (man-made glass)
Vitreous Silica with Chromium/Iron additives
mineralogical simulant
Granite
Granite (phaneitic intrusive igneous rock)
igneous