Porphyry (Flower Stone)
Porphyry (Andesite or Basalt matrix)
igneous
Category
Igneous, Sedimentary, And Metamorphic
Browse igneous, sedimentary, and metamorphic specimens identified by the Rock Identifier community.
Carnelian
Carnelian (a variety of Chalcedony, SiO ₂)
Mineral (specifically a variety of Chalcedony, which is a cryptocrystalline quartz)
Agate
Agate (a cryptocrystalline variety of Quartz, SiO₂)
Mineral
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Banded Agate (White Agate)
Chalcedony (Silicon Dioxide, SiO2)
mineral
Pink Tourmaline (Rubellite)
Elbaite (Tourmaline group) - Na(Li,Al)3Al6(BO3)3Si6O18(OH)4
mineral
Black Obsidian and Hematite
Volcanic Glass (SiO2) and Hematite (Fe2O3)
igneous and mineral
Silver (Native Element)
Ag (Argentum)
mineral
Quartz / Milky Quartz
Silicon Dioxide (SiO2)
mineral
Amazonite
KAlSi3O8 (Potassium aluminum silicate - blue-green variety of Microcline)
mineral
Schorl (Black Tourmaline)
NaFe3Al6Si6O18(BO3)3(OH)3OH (Iron tourmaline)
mineral
Aventurine (Tan/Cream colored)
Quartz (SiO2) with mineral inclusions
mineral
Aventurine
Silicon Dioxide (SiO2) with inclusions
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Aquamarine
Beryl (Be3Al2Si6O18 with iron impurities)
mineral
River Pebble (Likely Quartzite or Chert)
Silicon Dioxide (SiO2)
metamorphic or sedimentary
Glacial Erratic (Sandstone/Quartzite)
Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)
sedimentary or metamorphic
Weathered Quartzite or Chert Pebble
Silicon Dioxide (SiO2)
metamorphic or sedimentary
Limonite-stained Quartz / Quartzite
Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)
sedimentary or metamorphic
River Cobble (likely Quartzite or Limestone)
SiO2 (Quartzite dominant) or CaCO3 (Limestone dominant)
metamorphic or sedimentary
Wishing Stone (Basalt or Mudstone with Quartz/Calcite Veins)
Hydrothermally veined Basalt (SiO2/CaCO3 intrusions)
igneous or sedimentary
Tiger's Eye and Carnelian Quartz
Silicon Dioxide (SiO2)
metamorphic and mineral
Black Chert
Chert (microcrystalline quartz)
Mineral
Amethyst
Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities
Mineral
Epidote
Epidote - Ca2(Al,Fe)3(SiO4)3(OH)
metamorphic
Citrine
Quartz (SiO2) - variety Citrine
Mineral
Amazonite
Amazonite (KAlSi3O8, a variety of Microcline)
Mineral
River Rock (Glacial Cobbles)
Fluvial Alluvium (Mixed lithology including Quartzite, Basalt, and Granite)
Mixed (predominantly sedimentary and igneous)
Amazonite
K(AlSi3O8) - Potassium Aluminum Silicate
mineral
Serpentine
Serpentine group ((Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4)
metamorphic
Aventurine and Amazonite
Silicon Dioxide (SiO2) with inclusions and Microcline (KAlSi3O8)
Mineral
River Pebble (Quartzite/Siltstone mixture)
Silicon Dioxide (SiO2) mixture with varied clastic minerals
sedimentary/metamorphic
Micaceous Sandstone or Quartzite
Sandstone (lithified quartz grains, often with mica) or Quartzite (metamorphosed sandstone)
Sedimentary or Metamorphic
River Pebble (likely Quartzite or Chert)
Silicon Dioxide (SiO2) crystal conglomerate
sedimentary or metamorphic
Quartzite and Chert
Silicon Dioxide (SiO2)
metamorphic and sedimentary
Quartz (Common or Milky)
Silicon Dioxide (SiO2)
mineral
River Pebble (Basalt/Greywacke)
Weathered Basalt or Fine-Grained Greywacke
igneous/sedimentary
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
mineral
Quartzite
Quartzite
Metamorphic rock
Quartzite
Quartzite (SiO2)
metamorphic
Pebble (Likely Basalt or Siltstone)
Clastic sedimentary rock or mafic volcanic rock
Igneous or Sedimentary
Quartz with Mica/Chlorite inclusions
Silicon Dioxide (SiO2) with phyllosilicate inclusions
igneous/metamorphic mineral specimen