Basalt
Basalt (predominantly Plagioclase Feldspar and Pyroxene)
igneous
Category
Mineral, Often A Rock Given Its Aggregate Nature
Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.
Mica Schist
Muscovite/Biotite Schist
metamorphic
Basalt (Weathered/River worn)
Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)
igneous
Sedimentary Breccia
Clastic Breccia (CaCO3/SiO2 matrix)
sedimentary
Basalt with Amygdaloidal Inclusions
Aphanitic Mafic Volcanic Rock (Basalt)
igneous
River Quartz (Milky and Smoky mix)
Silicon Dioxide (SiO2)
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
Mineral / Sedimentary occurrence
Tiger's Eye (Mineral Collection)
Tiger's Eye (SiO2 with crocidolite inclusions)
mineral
Celestine (Celestite)
Strontium sulfate (SrSO4)
mineral
Red Jasper
Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)
sedimentary
Jasper Breccia
Silicon Dioxide (SiO2) with impurities
sedimentary
River Rocks (Basalt and Sedimentary Stones)
Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock
igneous and sedimentary
Manganese Oxide Crust on Limestone
Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3
sedimentary
Biotite Schist
Biotite Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
metamorphic
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
mineral
Basalt (with possible mineral veining)
Basalt (Aphanitic Mafic Igneous Rock)
Igneous
Boxwork Siderite or Sepatarian Nodule Weathering
Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment
sedimentary
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of iron oxide)
metamorphic
Golden Sheen Obsidian
Obsidian (volcanic glass) with inclusions of gas bubbles and mineral crystals (e.g., hematite, magnetite) causing the sheen
igneous
Quartz Geode (River Cobble)
Silicon Dioxide (SiO2)
mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
mineral
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
mineral
Chert (Nodular or Massive Variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Fluorite Bracelet (light green beads) and possibly Lavender Jadeite (purple bead)
Fluorite: CaF₂ (Calcium Fluoride); Jadeite: NaAlSi₂O₆ (Sodium Aluminum Silicate)
Mineral for Fluorite; Mineral/Rock for Jadeite (as it's often a rock composed primarily of jadeite mineral)
Granite
Phaneritic Felsic Igneous Rock
igneous
Sandstone (Ferruginous)
Arenite (variable SiO2 with Fe2O3 staining)
sedimentary
Banded Gneiss (Variety of Gneiss)
Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)
Metamorphic Rock
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Basalt
Basalt (Mafic volcanic rock)
igneous
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Granite
Granite (Felsic Plutonic Rock)
igneous
Jasper (Yellow Jasper)
Silicon Dioxide (SiO2) with iron inclusions
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite or Limonite inclusions
sedimentary
Sandstone (Ferruginous)
Arenite (with Iron Oxide cement)
sedimentary
Scoria (Lava Rock)
Scoria (Extrusive Igneous Rock / Mafic Silicates)
igneous
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Quartz (River Stone)
Silicon Dioxide (SiO2)
mineral
Lava Rock (Scoria)
Scoria (Vesicular Basalt)
igneous
Basalt
Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)
igneous
Sandstone
Arenite (a specific type of sandstone with less than 15% matrix)
Sedimentary rock