Rutilated Quartz (likely Citrine or Smoky Quartz with Rutile inclusions)
SiO2 with TiO2 inclusions (Quartz with Rutile)
Category
Browse igneous, sedimentary, and metamorphic specimens identified by the Rock Identifier community.
Rutilated Quartz (likely Citrine or Smoky Quartz with Rutile inclusions)
SiO2 with TiO2 inclusions (Quartz with Rutile)
Fired Clay Brick (Anthropic Rock substitute)
Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)
Calcite (likely a tumbled specimen)
Calcite (CaCO 3 )
Quartz Pebble (Iron-stained)
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe) impurities
Red Agate
Agate (Cryptocrystalline variety of Quartz, SiO2)
Peach Aventurine
Quartz variety (SiO2 + Hematite/Goethite inclusions)
Quartz (River-worn Pebble)
Quartz (SiO2)
Quartzite
Quartzite (Mainly SiO2)
Quartz Geode
Silicon Dioxide (SiO2) in a Geode body
Milky Quartz (Common Quartz/Crystalline Quartz)
Quartz (Silicon Dioxide, SiO2)
Moonstone
Orthoclase Feldspar (composed of alternate layers of orthoclase and albite), (K,Na)AlSi3O8
Beryl (likely Aquamarine) in matrix
Be3Al2(SiO3)6 (Beryllium Aluminum Silicate)
Moonstone (Feldspar)
Orthoclase/Albite ((K,Na)AlSi3O8)
Lapis Lazuli
A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).
Jasper (specifically Polychrome or Desert Jasper)
Silicon Dioxide (SiO2) with impurities
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Quartz (Milky/Bull Quartz)
Silicon Dioxide (SiO2)
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
Quartzite
Quartzite (primarily SiO2)
Quartz Geode (with Agate banding)
Silicon Dioxide (SiO2)
Orange Quartz with Epidote
Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate hydroxide (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
Aquamarine
Beryl (Be3Al2Si6O18 with iron impurities)
Banded Agate (variety of Chalcedony)
Agate (SiO2)
Agate (Slab)
Agate (Cryptocrystalline variety of Quartz, SiO2)
Engineer Quartz/Quartzite
SiO2 (Silicon Dioxide with binders)
Jasper and Aquamarine (likely)
Jasper (Cryptocrystalline Quartz (SiO2)), Aquamarine (Beryl (Be3Al2Si6O18))
Sapphire (likely blue synthetic sapphire or blue glass in a ring)
Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.
Diorite (possibly fine-grained variety or a related intermediate intrusive rock like a felsic gabbro or a dark granodiorite)
Diorite (Igneous rock, intrusive, intermediate composition)
Red Chalcedony (likely dyed)
Chalcedony (a variety of Quartz), SiO2
Quartz Geode/Druzy Quartz
Quartz (SiO₂)
Dendritic Agate
Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2 + Mn/Fe)
Jasper (Wonderstone/Banded Jasper)
Silicon Dioxide (SiO2) with iron oxide impurities
Thunderegg (Ate Agate/Jasper Geode)
Silicon Dioxide (SiO2) within Rhyolite/Perlite matrix
Thunderegg (Agate-filled Geode Node)
Silicon dioxide (SiO2) with various inclusions
River Cobbles (Basalt, Quartzite, and Sandstone mix)
Fluvial detritus (primarily SiO2, Plagioclase, and Pyroxene mix)
Limonitic Gossan
Goethite/Limonite aggregate after sulfide
Unakite (often traded as Dragon Blood Jasper)
Epidotized Granite
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) in matrix
Quartzite
Quartzite (primarily SiO2)
Green Aventurine
Quartz (Aventurine variety) - SiO₂ with Fuchsite inclusions
Amethyst
Amethyst is a variety of Quartz (SiO₂)