Sapphire (Corundum)
Corundum (Al2O3), variety Sapphire
Mineral
Category
Igneous, Sedimentary, And Metamorphic
Browse igneous, sedimentary, and metamorphic specimens identified by the Rock Identifier community.
Amazonite
Microcline (KAlSi3O8) with Pb impurities
mineral
Moonstone
Orthoclase (Potassium Aluminum Silicate), Formula: (K,Na)AlSi3O8
mineral
Carnelian Agate
Silicon Dioxide (SiO2) with iron oxide inclusions
mineral
Green Tourmaline
Verdelite (Silicate mineral); Na(Li,Al)3Al6(BO3)3Si6O18(OH)4
mineral
Muscovite Mica (with Quartz matrix)
Muscovite - KAl2(AlSi3O10)(OH)2
mineral
Botryoidal Chalcedony
Chalcedony (SiO2)
Mineral
Agate (various color varieties)
SiO₂ (Silicon Dioxide)
Mineral (specifically a variety of Chalcedony, which is a microcrystalline quartz)
River Stone (likely Basalt or Chert)
Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt
igneous/sedimentary
River Pebble (Greywacke or Basaltic)
Massive Greywacke or Basaltic Andesite
sedimentary or igneous
Painted River Pebble (likely Basalt or Greywacke)
Aphanitic Lithic Clast with Anthropogenic Pigment coating
Sedimentary or Igneous
Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)
Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein
igneous or sedimentary
Granite (phaneritic background) with Limestone/Calcite carving
Felsic Igneous Plutonic Rock (background) / Calcium Carbonate (CaCO3) (carving)
igneous and sedimentary
Agate
Silicon Dioxide (SiO2)
mineral
Amazonite
K(AlSi3O8) - Microcline variant
mineral
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Banded Agate
Chalcedony (Silicon Dioxide, SiO2)
mineral
Agate
Chalcedony (SiO2)
mineral
Muscovite (Mica) in Quartz Matrix
Muscovite (KAl2(AlSi3O10)(OH)2) and Quartz (SiO2)
mineral
Calcite
Calcite (Mineral; CaCO₃)
Mineral
Marble
Metamorphic rock composed of Recrystallized Carbonate Minerals (chiefly CaCO3)
metamorphic
Epidote
Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
Mineral
River Pebbles (Tumbled Quartz and Basalt)
Silicon Dioxide (SiO2) for white quartz; Mafic Volcanic Rock for basalt
igneous and sedimentary
Wishing Stone (Basalt/Greywacke with Quartz Vein)
Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion
igneous/sedimentary
River Rock (Basalt/Greywacke pebbles)
Fluvial gravel primarily composed of Mafic Volcanic Rock (Basalt) or Lithic Sandstone (Greywacke)
igneous and sedimentary
Dendritic Agate (or Dendritic Opal)
SiO2 (for Agate), SiO2·nH2O (for Opal)
Mineral
Metal Chain (Likely Steel or a Steel Alloy)
Steel (primarily iron and carbon); specific alloy unknown
Man-made Object (Metal/Alloy)
Calcite
Calcite (CaCO 3)
Mineral
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Mineral (or mineraloid if microcrystalline)
Quartz (Milky/Iron-stained)
Silicon Dioxide (SiO2)
mineral
Aquamarine
Beryl (Be3Al2Si6O18 with iron impurities)
mineral
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Yellow Agate
Silicon Dioxide (SiO2)
mineral
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Green Aventurine
Aventurine Quartz (SiO2 + Fuchsite mica)
Mineral
Aquamarine
Beryl (Be3Al2Si6O18 with iron traces)
mineral
Serpentinite
Serpentinite (composed primarily of Serpentine minerals: Mg3Si2O5(OH)4)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Ruby
Corundum (Al₂O₃) with Chromium (Cr)
Mineral (gemstone)
Green Agate
Silicon Dioxide (SiO2) - Chalcedony variety
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Peach Moonstone
Potassium Aluminum Silicate (KAlSi3O8); variety of Orthoclase Feldspar
mineral