Bauxite Ore
Hydrated aluminum oxides (e.g., Gibbsite Al(OH)3, Boehmite ̲̲̲̲AlOOH, Diaspore ̲̲̲̲AlOOH)
Category
Browse synthetic or natural fiber specimens identified by the Rock Identifier community.
Bauxite Ore
Hydrated aluminum oxides (e.g., Gibbsite Al(OH)3, Boehmite ̲̲̲̲AlOOH, Diaspore ̲̲̲̲AlOOH)
Turquoise, Pearl, and Coral Necklace
CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)
Basalt (River Pebble)
Extrusive mafic igneous rock
Tanzanite
Blue Zoisite (Ca2Al3(SiO4)3(OH))
Orange Calcite (likely polished specimen)
Calcite
Geode (unopened nodule)
Silicon Dioxide (SiO2) Nodule
Porphyritic Rhyolite (Birdseye Rhyolite)
Rhyolite (Porphyritic texture)
Echinoidea (Fossil Sea Urchin)
Echinodermata Echinoidea
Caribbean Calcite
Calcite (CaCO3) with Aragonite (CaCO3)
Milky Quartz
Silicon Dioxide (SiO2)
Fossilized Brachiopod
Phylum Brachiopoda (replaced by Calcite/CaCO3)
Amethyst or Smoky Quartz Geode Slice
Crystalline Silicon Dioxide (SiO2) with iron impurities
Sandstone (Yellow/Siltstone variant)
Arenite (SiO2 primarily)
Chert (including varieties like Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Tumbled Carnelian and Quartz Mix
Silicon Dioxide (SiO2) with iron oxide impurities
Quartz (Iron-stained)
Silicon Dioxide (SiO2) with hematite/limonite inclusions
Conglomerate
Conglomerate (clastic sedimentary rock)
Graphite
Graphite (C)
Quartz / Milky Quartz
Silicon Dioxide (SiO2)
Diorite (Dalmatian Stone variant)
Phaneritic Plutonic Igneous Rock (Medium to Fine-grained Diorite)
Basalt with vesicles
Vesicular Basalt
Gold
Native Gold (Au)
Sandstone
Arenite (primarily SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Amber and Citrine Quartz
Succinite (Amber) and Silicon Dioxide (SiO2 / Citrine)
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Quartz-veined Siltstone/Greywacke
Clastic Sedimentary Rock with Quartz Infill (SiO2 vein)
Sandstone with Ironstone Banding
Clastic Sandstone (composed of Quartz with Hematite/Limonite bonding)
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
Sandstone (likely Arkose)
Arenite (Feldspathic Sandstone / Arkose)
Amethyst Geode
Silicon Dioxide (SiO2) with iron impurities
Basalt (with possible iron oxide staining)
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Chert (Flint)
Microcrystalline silica (SiO2)
Obsidian
Volcanic Glass (predominantly SiO2)
Moonstone
Orthoclase Feldspar ((K,Na)AlSi3O8)
Peridot
Olivine ((Mg, Fe)2SiO4)
Gold Nugget
Native Gold (Au)
Amber (Burmite)
Fossilized tree resin (Succinite variant)
Chert (varieties include Flint and Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Basalt River Pebble
Basalt (Aphanitic Mafic Igneous Rock)
Fulgurite
Lechatelierite (Silica glass), typically SiO2
Yellow Quartzite Pebble
Quartzite (primarily SiO2)