Fluorite
Calcium Fluoride (CaF2)
mineral
Category
Mineraloid (Human Made Geological Specimen)
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Diamond
Diamond (pure Carbon, C)
mineral
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with Fe2O3/FeO(OH) cement)
sedimentary
Mixed polished river pebbles, predominantly quartzite and quartz
Quartzite (SiO₂), quartz (SiO₂), with possible feldspar-rich and iron-stained lithologies
metamorphic
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Citrine (Heat-treated Amethyst)
Quartz (Silicon Dioxide, SiO2)
mineral
Pink Granite (Water-Worn)
Felsic Plutonic Rock (Potassium Feldspar-rich)
igneous
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Calcite
Calcium Carbonate (CaCO3)
mineral
Honey Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Milky Quartz (Druzy Geode fragment)
Silicon Dioxide (SiO2)
mineral
Aura Rose Quartz
SiO2 (Silicon Dioxide with Titanium/Gold coating)
mineral
Chert (Arrowhead variety)
Chert (SiO2)
sedimentary
Sandstone (Quartzite Pebble)
Arenite / Metamorphosed Sandstone (SiO2)
sedimentary
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Mineral
Pegmatite
Pegmatitic Granite
igneous
Pink feldspar-bearing granite or pegmatite fragment
Mostly potassium feldspar (orthoclase/microcline), quartz, and minor mica; exact identification requires testing
igneous
Red Quartzite / Ferruginous Sandstone
Quartzite (SiO2 with iron oxide impurities)
metamorphic
Rough Diamond
Diamond (pure Carbon, C)
mineral
Diamond
Native Carbon (C)
mineral
Basalt
Basalt (Mafic volcanic rock)
igneous
Blue sodalite-bearing rock, likely sodalite in nepheline syenite
Sodalite (Na₈Al₆Si₆O₂₄Cl₂), possibly in nepheline syenite
mineral
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
igneous
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Green Jasper (with Quartz veining)
Jasper (Silica-rich microcrystalline variety of Quartz), formula: SiO2
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Faceted yellow-brown gemstone earring
Likely citrine (quartz, SiO₂), though treated quartz or synthetic glass cannot be confirmed from the image
gemstone
Porcelain (White Ceramic)
Mullite-bearing Vitrified Ceramic (Major phases: Mullite Al6Si2O13, Glassy Silica SiO2)
metamorphic
Amber
Succinite (C10H16O)
Organic Mineraloid
Sea Glass
Amorphous Silica (SiO2) with various additives
Mineraloid (Anthropogenic)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 (Lithium-bearing Mica)
mineral
Cloudy Quartz / Quartz Tumble
Silicon Dioxide (SiO2)
mineral
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
River Siltstone / Mudstone Pebble
Siltstone (composed of mixed silicate and carbonate minerals)
sedimentary
Rounded river pebble
Indeterminate; likely quartz-rich sandstone, chert, or weathered volcanic rock
sedimentary
Serpentinite (likely)
Serpentinite, dominated by serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and relic olivine/pyroxene
metamorphic
Diamond (set in Gold)
Diamond (pure carbon, C)
mineral
Limonite
Limonite (Hydrous iron oxides, FeO(OH)·nH2O)
mineral
Granite
Granite (a phaneritic intrusive igneous rock)
igneous
Milky quartz (rough quartz specimen)
Quartz, silicon dioxide (SiO₂)
mineral
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Ferruginous Sandstone (Ironstone Nodules)
Ferruginous Sandstone with Limonite/Goethite coating (Fe2O3·H2O)
sedimentary