Calcite
Calcite (Mineral; CaCO₃)
Category
Browse sedimentary (silica rich mineral variety) specimens identified by the Rock Identifier community.
Calcite
Calcite (Mineral; CaCO₃)
Jasper and Quartz River Pebble
Silicon Dioxide (SiO2) with impurities
Sandstone (Stream-rounded)
Arenite (SiO2 based)
Sandstone (Greywacke)
Arenite / Clastic Sedimentary Rock
Banded Agate (River-worn Pebble)
Cryptocrystalline Silicon Dioxide (SiO2)
Wishing Stone (Quartz-veined Siltstone or Graywacke)
Hydrothermal Quartz vein in matrix of SiO2 (Quartz) and Al2O3 (Clay minerals)
Fuchsite
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
Sandstone (Ferruginous/Red Sandstone)
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
Jasper (Red/Yellow)
Silicon Dioxide (SiO2) with impurities
Agate
Silicon Dioxide (SiO2)
Chrysoprase
Chalcedony (cryptocrystalline silica containing nickel); Chemical Formula: SiO2 with Ni impurities
Vesicular Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock)
Chert (specifically Jasper/Flint pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Limonite (Iron Stone Concretion)
Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O
Blue Aventurine
Quartzite with Dumortierite inclusions (SiO2)
Black Onyx
Silicon Dioxide (SiO2) with cryptocrystalline structure
Quartz
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 based)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (often referred to as Flint)
Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)
Chert (Nodular)
Cryptocrystalline Quartz (SiO2)
Orbicular Rhyolite (Rainforest Jasper)
Rhyolite containing Spherulites (SiO2 with impurities)
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Nephrite Jade
Nephrite (a variety of the mineral actinolite within the amphibole group); Chemical Formula: Ca2(Mg,Fe)5Si8O22(OH)2
Carnelian
SiO2 (Silicon Dioxide) - Translucent reddish-brown variety of Chalcedony
Opalite (Synthetic Moonstone/Opal)
Synthetic Silica Glass
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
Yellow Jade (often Serpentine or Dolomite)
Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.
Schorl (Black Tourmaline)
NaFe3Al6Si6O18(BO3)3(OH)3OH (Iron tourmaline)
Green Aventurine
Quartz (SiO2) with Fuchsite inclusions
Jasper / Chert (River Pebble)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (specifically Blue Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
River Stone (River Pebbles)
Alluvial Deposit (typically Quartzite, Sandstone, or Granite clasts)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 inclusions)
Mahogany Obsidian
Volcanic Glass (Silicate: SiO2 + Fe2O3)
Chert (Iron-stained)
Microcrystalline silica (SiO2) with trace Iron oxide (Fe2O3)
Sandstone
Arenite (composed primarily of SiO2)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)
Iron Ore (Limonite and Hematite)
Goethite/Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)
Carnelian Agate
Silicon Dioxide (SiO2) with Iron Oxide impurities
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Yellow Quartz (Chalcedony/Agate)
Silicon Dioxide (SiO2)