Pearl
Aragonite (CaCO3 with conchiolin)
mineral
Category
Man Made Glass (Not A Natural Rock Or Mineral)
Browse man made glass (not a natural rock or mineral) specimens identified by the Rock Identifier community.
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Sandstone
Arenite (primarily SiO2)
sedimentary
Basalt
Basalt
igneous
Sandstone
Sedimentary Clastic Rock (Quartz Arenite)
sedimentary
Rough Amethyst
Silicon Dioxide (SiO2) with Iron impurities
mineral
White quartz pebble
Quartz (silicon dioxide, SiO₂), likely milky quartz
mineral
Mixed tumbled stone collection
Assorted minerals, likely including quartz, jasper, agate, and possibly obsidian or hematite
mineral
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Sandstone
Clastic Sedimentary Rock
sedimentary
Tumbled citrine or iron-stained quartz
Quartz (SiO₂), likely iron-oxide-stained or natural citrine
mineral
Polished citrine quartz point
Quartz, silicon dioxide (SiO₂), yellow-orange variety commonly sold as citrine; possibly heat-treated amethyst
mineral
Chert / Flint Nodule
Cryptocrystalline quartz (SiO2)
sedimentary
Yellow Quartz (Citrine/Yellow Jasper mix)
Silicon Dioxide (SiO2)
mineral
Sandstone (with potentially high Feldspar/Arkose content)
Clastic sedimentary rock (SiO2 dominated)
sedimentary
Granite
Intrusive Igneous Rock
igneous
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Milky and Citrine-type Quartz
Silicon Dioxide (SiO2)
mineral
Rock crystal quartz fragment
Quartz (silicon dioxide, SiO₂)
mineral
Nickel coin (U.S. currency)
Cupronickel (75% Copper, 25% Nickel alloy)
man-made alloy (metallic)
Polished ocean jasper / orbicular jasper
Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and other mineral inclusions
mineral
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide staining/cementing)
sedimentary
Sandstone with Iron Oxide Coating
Arenite (SiO2 with Fe2O3 impurities)
sedimentary
Diamond
Carbon (C)
gemstone
Orbicular granite (likely rapakivi-type granite)
Granite; chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende
igneous
Banded Chert (River Stone)
Silicon Dioxide (SiO2)
sedimentary
Sandstone (with Rock Art)
Sandstone (Clastic Sedimentary Rock)
sedimentary
Citrine (Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
River Pebble (Sandstone / Quartzite)
Sedimentary rock (Quartz arenite / Quartzite pebble)
sedimentary
Smoky Quartz (Tumbled)
Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite (siliciclastic sedimentary rock composed mostly of quartz)
sedimentary
Sandstone
Arenite
sedimentary
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
igneous
Smoky Quartz (Tumbled)
Smoky Quartz (SiO2 - Silicon Dioxide)
mineral
Sandstone
Clastic sedimentary rock (primarily quartz arenite)
sedimentary
Rounded quartz-rich pebble
Quartz (SiO₂), possibly a quartzite or light-colored chert pebble
mineral
Rough Diamond
Diamond (Pure Carbon: C)
mineral
Sandstone (likely Quartzose)
Arenite (primarily SiO2)
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral