Rough Diamond / Clear Quartz
C (Carbon) or SiO2 (Silicon Dioxide)
Category
Browse synthetic (not a natural rock) specimens identified by the Rock Identifier community.
Rough Diamond / Clear Quartz
C (Carbon) or SiO2 (Silicon Dioxide)
Rutilated quartz crystal
Quartz, silicon dioxide (SiO₂), containing rutile inclusions (TiO₂)
Black Onyx
Cryptocrystalline Quartz (SiO2)
Tumbled Peach Quartz
Silicon Dioxide (SiO2)
Quartz (Smoky/Clear variety)
Silicon Dioxide (SiO2)
Green Aventurine
Aventurine Quartz (SiO2 + Fuchsite inclusions)
Diamond
Carbon (C)
Tangerine Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite coatings
Quartz Druzy on Agate
Silicon Dioxide (SiO2)
Herkimer Diamond
Quartz (Silicon Dioxide) - SiO2
Tumbled zebra stone, likely zebra marble or banded calcite
Zebra marble (recrystallized calcite, CaCO₃), possibly black-and-white banded calcite
Howlite
Howlite (Ca2B5SiO9(OH)5)
Clear Quartz Crystal (Likely Golden Healer/Iron-Stained)
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Quartzite (Quartz Vein)
SiO2 (Silicon Dioxide)
Hematite
Iron(III) oxide (Fe2O3)
Weathered limestone pebble
Limestone, primarily calcite (CaCO₃)
Orange Sapphire
Corundum (Al2O3 with trace elements)
Green Tiger's Eye
Quartz (SiO2) with fibrous crocidolite inclusions (dyed)
Clear Quartz
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Glauconitic Sandstone
Greensand (Glauconite-bearing sandstone)
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Chalcedony mix)
Ferruginous Slag (Iron Smelting Byproduct)
Anthropogenic Vitreous Silicate (often containing Fayalite: Fe2SiO4)
Snowflake obsidian cabochon
Obsidian (volcanic glass), SiO₂-rich; white areas are cristobalite/spherulitic devitrification
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Quartz Geode
Silicon Dioxide (SiO2)
Rough Blue Diamond
Carbon (C) - Type IIb Diamond
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Green Aventurine
Quartz containing Fuchsite (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
Diamond
Carbon (C)
Dark gray rounded stone, possibly basalt or slag
Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or iron-rich industrial slag
Diamond (or Diamond Simulant)
Carbon (C) or Zirconium dioxide (ZrO2) for CZ
Red cabochon gemstone, likely carnelian or dyed chalcedony
Chalcedony (microcrystalline quartz), SiO₂; exact identification requires testing
Green Aventurine
Silicon Dioxide (Quartz with Fuchsite inclusions, SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Chert (Flint)
Silicon dioxide (SiO2)
Citrine
Silicon Dioxide (SiO2)
Limonite / Ironstone Nodule
Hydrated Iron Oxide (FeO(OH)·nH2O)
Green Aventurine
Silicon Dioxide (Quartz) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
Black Onyx
Cryptocrystalline Quartz (SiO2)
Red Jasper
Silicon dioxide (SiO2) with iron oxide inclusions