Quartz (specifically Milky/Gray Quartz)
Silicon Dioxide (SiO2)
mineral
Category
Mineral, Specifically A Detrital Grain
Browse mineral, specifically a detrital grain specimens identified by the Rock Identifier community.
Sandstone
Clastic Sedimentary Rock (composed mostly of SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Mineral
Hematite
Hematite (Fe2O3)
mineral
Sandstone (likely Quartzose Sandstone)
Arenite (SiO2 predominantly)
sedimentary
Diorite (River Cobble)
Intermediate plutonic igneous rock
igneous
Pebble (river rock/beach pebble)
Pebble (clast size class)
Sedimentary Rock
Quartz (specifically a water-worn river pebble)
Silicon Dioxide (SiO2)
Mineral
Banded Agate (specifically Lake Superior Agate)
Silicon dioxide (SiO2) - Cryptocrystalline Chalcedony
mineral
Banded Agate (specifically Lake Superior Agate type)
Silicon Dioxide (SiO2) - Microcrystalline Chalcedony
mineral
Banded Agate (specifically Lake Superior Agate style)
Silicon Dioxide (SiO2) - Chalcedony variety
mineral
Banded Agate (specifically Lace Agate type)
Silicon Dioxide (SiO2)
mineral
Obsidian (specifically Rainbow or Silver Sheen Obsidian)
Volcanic Glass (predominantly SiO2)
Igneous
Shale creek bed
Shale (fine-grained clastic sedimentary rock)
Sedimentary
Garnet (likely Almandine, Pyrope, or a blend)
Garnet group minerals: X3Y2(SiO4)3, where X and Y represent various metal ions (e.g., Almandine: Fe3Al2(SiO4)3, Pyrope: Mg3Al2(SiO4)3)
Mineral
Emerald
Beryl (Be3Al2Si6O18), specifically the green variety colored by chromium or vanadium
Mineral (Gemstone variety of Beryl)
Slag Glass
Glassy Silicate Residue
industrial byproduct
Marble
Recrystallized Calcite (CaCO3) Rock
metamorphic
Quartzite
Quartzite (Primary mineral: SiO2)
metamorphic
Olivine-bearing Basalt / Scoria
Mafic Igneous Rock (primarily (Mg, Fe)2SiO4)
igneous
Sandstone (Quartzose Sandstone Pebble)
Arenite (primarily SiO2)
sedimentary
Schist
Schist (primarily mica-schist)
metamorphic
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (Lithic arenite / Quartz arenite)
sedimentary
Tektite (specifically Indochinite)
Tektite (Natural silica glass)
Mineraloid (Impact glass)
Chert (specifically Flint)
Silicon dioxide (SiO2)
sedimentary
Chert (specifically Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Jasper)
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary
Chert (specifically Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Blue Goldstone
Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)
Synthetic (Man-made Glass)
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
igneous
Chert (Iron-stained)
Chert (Silicon Dioxide, SiO2)
sedimentary
Peridot (likely, based on color and appearance)
Olivine group mineral, specifically (Mg,Fe)2SiO4 (Forsterite-Fayalite solid solution series)
Mineral
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Sandstone
Arenite (composed primarily of Quartz: SiO2)
sedimentary
Diorite (possibly fine-grained variety or a related intermediate intrusive rock like a felsic gabbro or a dark granodiorite)
Diorite (Igneous rock, intrusive, intermediate composition)
Igneous Rock
Amber (Black)
Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)
Mineraloid
Diorite (Salt and Pepper Rock)
Diorite
igneous
Quartz (specifically Milky/Gray Quartz vein)
Silicon Dioxide (SiO2)
mineral
Sandstone (Ferruginous)
Arenite (iron-rich)
sedimentary
Sandstone (with Lichen)
Arenite (primarily SiO2)
sedimentary
Oolitic Limestone
Oolitic Limestone (Calcium Carbonate, CaCO3)
sedimentary