Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(OH)₄(BO₃)₃Si₆O₁₈)
Category
Browse synthetic (not a natural rock) specimens identified by the Rock Identifier community.
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(OH)₄(BO₃)₃Si₆O₁₈)
Orange Calcite
Calcite (CaCO3)
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron inclusions
Anthracite Coal
Anthracite (a variety of coal, predominantly carbon)
River Stone / Pebble
Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)
Granite
Granite (a plutonic igneous rock composed primarily of quartz and feldspar)
3D Printed PLA Elephant (Silk Multi-color)
Polylactic Acid (C3H4O2)n
Amethyst Sage Agate
Silicon Dioxide (SiO2) with trace minerals (Manganese/Iron oxides)
Amethyst Geode/Cluster
Quartz (SiO2) - variety Amethyst
Rhodonite
Rhodonite (MnSiO3)
Rough Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Silver (Jewelry Specimen)
Native Silver (Ag)
Diamond (in a jewelry setting)
Carbon (C)
Diamond
Carbon (C)
Diamond (in jewelry mount)
Carbon (C)
Pink Granite (Alkali Feldspar Granite)
Phaneritic Felsic Igneous Rock (composed primarily of KAlSi3O8, SiO2, and NaAlSi3O8)
Larimar
Pectolite (a blue variety of Pectolite)
Green Aventurine
Quartz (Aventurine variety) - SiO₂ with Fuchsite inclusions
Quartz (Engineered Stone Countertop)
Silicon Dioxide (SiO2) with polymer resins
Serpentinite (Serpentine Rock)
Primarily composed of serpentine group minerals, such as antigorite, chrysotile, and lizardite. Chemical formula for serpentine minerals is (Mg,Fe)3Si2O5(OH)4.
Lava Rock (Basalt)
Basalt (extrusive igneous rock)
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
Citrine Quartz (likely heat-treated)
Silicon Dioxide (SiO2)
Rhodonite beads (possibly dyed or treated, or lower quality Rhodonite)
Manganese inosilicate, (Mn,Fe,Mg,Ca)SiO3
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Sandstone (Red Arkose)
Sandstone (Arkose variant, primarily SiO2 with KAlSi3O8)
Brecciated Jasper
Silicon Dioxide (SiO2) with varying mineral inclusions (Iron Oxide, Hematite, Clay)
Anthracite Coal
Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Gold Nugget / Flake
Native Gold (Au)
Fossil Coral
Fossilized Scleractinia or Tabulata (various genera/species)
Amethyst (variety of Quartz)
SiO2 (Silicon Dioxide) with trace iron impurities
Quartzite
Quartzite (SiO2)
Marble
Marble (primarily Calcite, CaCO3 or Dolomite, CaMg(CO3)2)
Hematite (beads)
Hematite (Fe₂O₃)
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (primarily SiO2)
Red Cubic Zirconia (Simulated Garnet)
Zirconium Dioxide (ZrO2)
Travertine (often colloquially called Tufa)
Chemical Sedimentary Calcium Carbonate (CaCO3)
Slate
Slate (a fine-grained, foliated metamorphic rock). Mineral composition: Primarily composed of mica minerals (muscovite, chlorite, sericite) and quartz, with minor amounts of hematite, pyrite, and other accessory minerals.
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
Diamond (appearing in jewelry)
Diamond (pure Carbon, C)