Granite Cobble
Intrusive Igneous Rock (Felsic to Intermediate)
igneous
Category
Mineral, Specifically A Detrital Grain
Browse mineral, specifically a detrital grain specimens identified by the Rock Identifier community.
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Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Ruby (Corundum)
Corundum (Aluminum Oxide with Chromium), Al2O3:Cr
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Milky Quartz with Matrix
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (likely Rose or Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Pink Granite (Water-worn Cobble)
Phaneritic Felsic Intrusive Igneous Rock
igneous
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Green Aventurine
Quartz (SiO2) with fuchsite inclusions
mineral
Rose Quartz
Silicon dioxide with traces of titanium, iron, or manganese (SiO2)
mineral
Pegmatite (Granitic)
Granitic Pegmatite
igneous
Moonstone
Orthoclase and Albite (KAlSi3O8 / NaAlSi3O8)
mineral
Basalt
Basalt
igneous
Sandstone
Arenite (SiO2 based)
sedimentary
Quartz (likely Rose Quartz or Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Granite River Pebble
Granite (composed primarily of Quartz, Feldspar, and Mica)
igneous
Soapstone / Steatite
Steatite (primarily Talc, Mg3Si4O10(OH)2)
metamorphic
Citrine
Quartz (Silicon Dioxide - SiO2)
mineral
Granite (specifically Red Granite)
Phaneritic Plutonic Rock (High in Alkali Feldspar and Quartz)
igneous
African Turquoise
Jasper / Quartz matrix (Trade name: African Turquoise, chemically a form of microcrystalline quartz with various mineral inclusions)
gemstone
Basalt (Drill Core)
Mafic Volcanic Rock (Basalt)
igneous
Rounded river pebble
Indeterminate lithic clast; likely weathered sandstone or quartz-rich sedimentary rock
sedimentary
Sandstone (Micaceous)
Clastic Sedimentary Rock - Micaceous Litharenite (SiO2 principal)
sedimentary
Quartz Crystal
Silicon Dioxide (SiO2)
mineral
Blue glass-like tumbled specimen
Most likely cobalt-blue slag glass or manufactured glass; not confidently identifiable as a natural mineral from the image
mineral
Granite (likely weathered granite or granitic gneiss)
Granite; chiefly quartz (SiO₂), feldspar, and mica
igneous
Red Jasper
Microcrystalline Quartz (SiO2) with iron oxide inclusions
sedimentary
Baroque Pearl
Biogenic Calcium Carbonate (Aragonite/Conchiolin)
mineral
Black Tourmaline
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide)
mineral
Banded Agate
Cryptocrystalline Quartz (SiO2)
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Garnet
Almandine/Pyrope Garnet (X3Y2(SiO4)3)
mineral
Coprolite
Coprolite (fossilized feces)
fossil
Clear Quartz (or Rock Crystal)
Quartz (SiO₂)
Mineral
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
mineralological
Petrified Wood
Silicified Wood (SiO2)
sedimentary