Ruby
Corundum (Al2O3)
gemstone
Category
Not A Natural Rock (Man Made Composite)
Browse not a natural rock (man made composite) specimens identified by the Rock Identifier community.
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Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (primarily SiO2)
metamorphic
Red faceted gemstone jewelry setting
Likely synthetic ruby or red spinel centerpiece with colorless accent stones; exact identification requires gemological testing
gemstone
Diamond (in jewelry)
Diamond (Carbon, C)
mineral
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Mixed pebble collection, including likely flint, quartzite, and fossil material
Varied silicate rocks; visible specimen may include chert (microcrystalline SiO₂), quartzite, and a possible fossil
sedimentary
Likely polished dark pebble
Indeterminate; possibly basalt, black jasper, or a dark sulfide-rich stone
mineral
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Chalk
Micrite (primarily Calcium Carbonate or CaCO3)
sedimentary
Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Rough Diamond
Diamond (C - Carbon)
gemstone
Diamond
Diamond (C)
mineral
Coquina
Bioclastic Limestone
sedimentary
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 cement)
sedimentary
Fossiliferous Limestone / Fossil Fragment
Calcium Carbonate Matrix with Biogenic Inclusions (CaCO3)
fossil
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Crushed Limestone
Calcium Carbonate (CaCO3)
sedimentary
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Granodiorite / Granite (Weathered)
Granodiorite
Igneous
Ametrine
Silicon Dioxide (SiO2) with iron impurities
mineral
Coquina
Bioclastic Limestone
sedimentary
Granite
Granite
igneous
Tumbled Chalcedony Pebble
Silicon Dioxide (SiO2)
mineral
Granite
Granite (Mainly SiO2 and Al2O3)
igneous
Amethyst
Silicon dioxide (SiO2) with iron impurities
mineral
Chert or Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Tumbled ruby-bearing corundum
Corundum (Al₂O₃), likely ruby variety
mineral
Quartzite
Quartzite (SiO2)
metamorphic
River Stone
Water-worn lithic fragment
sedimentary
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Diamond
Carbon (C)
mineral
Red cabochon gemstone, likely carnelian or dyed chalcedony
Chalcedony (microcrystalline quartz), SiO₂; exact identification requires testing
gemstone
Tumbled yellow quartz (likely citrine or iron-stained quartz)
Quartz, silicon dioxide (SiO₂); yellow coloration likely from iron impurities
mineral
Agate
Banded Chalcedony (SiO2)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Diamond
Carbon (C)
mineral
Turquoise cabochon jewelry
Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O
gemstone
Smoky Quartz
Silicon Dioxide (SiO2)
mineral