Sandstone
Arenite (primarily SiO2)
sedimentary
Category
Not A Rock Or Mineral
Browse not a rock or mineral specimens identified by the Rock Identifier community.
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with inclusions of crocidolite or dumortierite
mineral
Gneiss (River Cobble)
Gneiss (Foliated Metamorphic Rock)
metamorphic
Granite
Granite (a common term for a felsic intrusive igneous rock)
igneous
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
Granite Thin Section
Granitic rock (Phaneritic texture)
igneous
Schist
Mica Schist
metamorphic
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
igneous
Sandstone (likely Graywacke or Arkose variant)
Clastic Sedimentary Rock (SiO2 with assorted lithic fragments)
sedimentary
Granite
Granite (Felsic Plutonic Rock)
igneous
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Quartz Druzy Geode Fragment
Silicon Dioxide (SiO2)
mineral
Granite
Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
igneous
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartzite / Sandstone / Chert Mix
Silicon Dioxide (SiO2)
sedimentary and metamorphic
Amethyst (Tumbled)
Amethyst (Silicon Dioxide, SiO2 + Fe4+)
mineral
Milky Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Mineral
Emerald in Matrix
Beryl (Be3Al2Si6O18) with trace amounts of Chromium/Vanadium
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Red Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
mineral
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock - Arenite
sedimentary
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)
igneous
Eudialyte in Matrix
Na15Ca6Fe3Zr3Si26O72(OH,Cl,H2O)3
mineral
River Stone (likely Siltstone or fine-grained Sandstone)
Clastic Sedimentary Rock (Lithic Wacke / Siltstone)
sedimentary
Agate
Silicon dioxide (SiO2)
mineral
Blue Lace Agate
Silicon dioxide (SiO2) - Chalcedony variety
mineral
Gold Nugget Jewelry
Native Gold (Au)
mineral
Thunderegg (specifically a Jasper/Agate-filled Geode nodule)
Silicon Dioxide (SiO2) within Rhyolitic Matrix
igneous
Banded Agate (specifically Carnelian Agate color)
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Sandstone (Ferruginous/Banded)
Clastic Terrigenous Sandstone (SiO2 with Fe2O3 cement)
sedimentary
Dalmation Stone
Peralkaline Rock (SiO2 with Arfvedsonite)
igneous
Serpentinite
Serpentinite (group of hydrous magnesium iron phyllosilicates)
metamorphic
Serpentinite
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Garnet Schist or Garnet-bearing Quartzite
Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)
metamorphic
Ruby in Zoisite with Hornblende
Anyolite (Ruby: Al2O3, Zoisite: Ca2Al3(SiO4)3(OH))
metamorphic
Almandine Garnet in Schist
Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist
metamorphic
Basalt with Quartz Veins
Basalt (SiO2 range 45-52%)
igneous
Quartz Vein in Host Rock (Likely Slate or Shale)
Hydrothermal Quartz (SiO2) in Pelitic host rock
metamorphic