Aquamarine on Feldspar Matrix
Beryl (Be3Al2Si6O18) with Potassium Feldspar (KAlSi3O8)
mineral
Category
Mineral Based Alloy (Anthropogenic)
Browse mineral based alloy (anthropogenic) specimens identified by the Rock Identifier community.
Ferruginous Sandstone (with possible trace fossils)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)
sedimentary
Muscovite Schist
Muscovite Mica Schist (KAl2(AlSi3O10)(OH)2)
metamorphic
Mica-rich Sandstone or Micaceous Schist Weathering
Micaceous Schist (Muscovite-Quartz composition)
Metamorphic or Sedimentary depending on local grade
Mica Schist
Mica Schist (Main mineral constituents: Muscovite/Biotite, Quartz, Feldspar)
metamorphic
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
mineral
Citrine Quartz
Silicon Dioxide (SiO2)
mineral
Schist
Mica Schist (primarily Muscovite and Quartz)
metamorphic
Sandstone (Quartz-rich Pebble)
Arenite (primarily SiO2)
sedimentary
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Conglomerate (River Rock Aggregate)
Conglomerate (Lithic-clast conglomerate)
sedimentary
Chert (variations include Chalcedony and Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
River Pebble (Likely Chert or Fine-Grained Sandstone/Quartzite)
Siliciclastic clast (likely Chert or Quartzarenite/Quartzite pebble)
Sedimentary
Schist
Mica Schist
metamorphic
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Organic Mineraloid
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Sandstone
Arenite (Siliclastic sedimentary rock, primarily SiO2)
sedimentary
Granite
Phaneritic Plutonic Rock (Granite)
igneous
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)
metamorphic
Muscovite Schist
Muscovite (KAl2(AlSi3O10)(OH)2) in Schist
metamorphic
Efflorescence (on Clay Brick)
Crystalline salt deposits (typically Sodium Sulfate Na2SO4, Calcium Carbonate CaCO3, or Potassium Sulfate K2SO4)
Mineral precipitate (anthropogenic context)
Granite
Phaneritic Plutonic Rock (High Silica content)
igneous
Mica (likely Muscovite)
Muscovite / KAl2(AlSi3O10)(OH)2
mineral
White Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Granite
Phaneritic Felsic Igneous Rock
igneous
Quartz with Mica inclusions (Gold-colored Mica)
Silicon Dioxide (SiO2) with Potassium Aluminum Silicate (Phlogopite/Muscovite) inclusions
Mineral
Banded Agate (specifically Moss Agate or Plume Agate variety)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Dalmatian Stone
Peralkaline Quartz-Feldspar Rock with Arfvedsonite
igneous
Limonite-stained Granite
Felsic Plutonic Rock with Hydrated Iron Oxides
igneous
Schist
Mica Schist (contains muscovite/biotite and quartz)
metamorphic
Ferruginous Breccia
Breccia with Iron-rich (Hematite/Goethite) Matrix
sedimentary
Granite (specifically Rapakivi Granite)
Phaneritic Felsic Igneous Rock (Granite)
igneous
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Granite
Felsic Intrusive Igneous Rock
igneous
Pink Granite
Granite (Phaneritic intrusive rock rich in K-feldspar)
igneous
River Siltstone / Mudstone Pebble
Siltstone (composed of mixed silicate and carbonate minerals)
sedimentary
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Agate (or Banded Agate)
Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)
Mineral, specifically a Cryptocrystalline Quartz variety
Quartz with Muscovite Mica
Silicon Dioxide (SiO2) with Potassium Aluminum Silicate Hydroxide Fluoride (KAl2(AlSi3O10)(F,OH)2)
mineral