Tumbled gray-green metamorphic rock, likely serpentinite or chlorite schist
Serpentinite/chlorite-rich ultramafic metamorphic rock; commonly dominated by antigorite, lizardite, or chlorite with minor magnetite and talc
metamorphic
Category
Synthetic Material (Not A Rock Or Mineral)
Browse synthetic material (not a rock or mineral) specimens identified by the Rock Identifier community.
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Cullet Glass (Strawberry Glass)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Mineraloid (Synthetic/Man-made)
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
mineral
River Rocks (Polished River Pebbles)
Stream-rounded clastic sediments
Mixed (Sedimentary, Igneous, and Metamorphic)
Banded gneiss pebble
Gneiss, commonly quartz–feldspar–mica gneiss
metamorphic
Rose Quartz
Rose Quartz (SiO2)
mineral
Quartzite Pebble
Metamorphic Quartzite (SiO2)
metamorphic
Granite Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Aventurine
Aventurine Quartz (SiO2 with inclusions)
metamorphic
Weathered sandstone or iron-stained siltstone
Quartz-rich clastic sedimentary rock, likely ferruginous sandstone
sedimentary
Weathered chert or silicified limestone nodule
Microcrystalline quartz (SiO₂), possibly replacing limestone; exact identification requires testing
sedimentary
Pyrite (on host rock)
Iron Sulfide (FeS2)
mineral
Amethyst Geode
Amethyst (Silicon Dioxide), Formula: SiO2
mineral
Calcite
Calcium Carbonate (CaCO3)
mineral
Red Jasper
Jasper (Silicon Dioxide, SiO2 with Fe2O3 inclusions)
mineral
Ironstone Concretion / Goethite-Hematite Nodule
Goethite/Hematite (α-FeO(OH) / Fe2O3)
sedimentary
Tumbled jasper or brecciated jasper
Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and dark mineral inclusions
mineral
Siltstone with Quartz Vein
Siltstone (primarily SiO2, Al2O3, Fe2O3)
sedimentary
Man-made Metal Pin (Non-geological)
Antimony-Lead Alloy or Zinc/Brass Base with Electroplating
Metal Alloy / Manufactured Artifact
Tumbled quartz pebble
Quartz (SiO₂), likely milky or fractured rock crystal
mineral
Red Sandstone (Siltstone pebble)
Arenite / Siltstone (Silicon dioxide based with hematite impurities)
sedimentary
Sandstone
Arenite (primarily SiO2, silica)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Diorite (River Cobble)
Intermediate plutonic igneous rock
igneous
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with Fe2O3)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Diorite
Plutonic Igneous Rock (NaAlSi3O8, CaAl2Si2O8)
igneous
Polished turquoise
Turquoise — hydrated copper–aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O
gemstone
Sandstone (Red Sandstone)
Arenite (primarily Quartz with Hematite cement)
sedimentary
Granite
Phaneritic plutonic rock (SiO2 typically >69%)
igneous
Vesicular volcanic rock, likely weathered pumice or scoria
Pumice/scoria; predominantly volcanic glass and feldspar, with possible iron oxides
igneous
Granite Pebble
Granite
igneous
Likely chlorite-bearing schist (possibly greenschist)
Chlorite–quartz–mica schist; commonly contains muscovite/biotite and feldspar
metamorphic
Weathered granite or granitic gneiss
Granite; chiefly quartz, feldspar, and mica (possibly gneissic if foliation is confirmed)
igneous
Basalt
Mafic volcanic rock (various silicate minerals)
igneous
Foliated metamorphic rock, likely biotite schist
Mica schist, chiefly quartz, feldspar, and biotite mica
metamorphic
Basalt (Greenstone)
Mafic volcanic rock (Basalt)
igneous
Hag Stone
Perforated Sedimentary Rock (typically Limestone or Sandstone)
sedimentary
Chert (Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Granite Pebble
Granite (Felsic intrusive igneous rock)
igneous
Likely quartz-rich metamorphic rock (quartzite or quartz-veined schist)
Quartzite/siliceous schist; chiefly quartz (SiO₂), with probable mica and iron-oxide staining
metamorphic
Siltstone with Iron Staining
Siltstone (primarily SiO2 with Fe2O3 staining)
sedimentary