Carnelian Agate
Silicon Dioxide (SiO2) - Chalcedony containing Iron Oxide impurities
mineral
Category
None
Browse none specimens identified by the Rock Identifier community.
Learn about None in the encyclopedia
View all →
Indian Agate
Cryptocrystalline Quartz (SiO2)
mineral
Sapphire
Corundum (Al2O3)
mineral
Greenstone (Celadonite-bearing Volcanic)
Hydrothermally altered basalt or andesite with Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Red Sandstone
Clastic Terrigenous Sedimentary Rock (primarily SiO2 with Fe2O3 coating)
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Unakite
Unakite (Epidotized Granite)
metamorphic
Corundum (variety Ruby/Sapphire)
Aluminum Oxide (Al2O3)
mineral
Goldstone
Avventurina (Cu + SiO2 glass)
mineral
Polished Ocean Jasper
Orbicular Jasper (variety of Chalcedony/Quartz, SiO2)
mineral
Obsidian
Volcanic Glass (SiO2, usually >70% silica content)
Igneous
Picture Jasper
Impure variety of silica (SiO2)
sedimentary
Jasper with Hematite inclusions
Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3)
sedimentary
Pink Opal
Hydrated Silica (SiO2·nH2O) with Palygorskite inclusions
Mineraloid
Chert (specifically Flint or Common Chert node)
Silicon Dioxide (SiO2)
sedimentary
Conglomerate
Clastic Sedimentary Conglomerate (SiO2, CaCO3, etc.)
sedimentary
Pumice
Pumice (a highly vesicular amorphous volcanic glass)
igneous
Sandstone (Weathered Coastal Boulder)
Arenite (composed primarily of SiO2)
sedimentary
Limonite (Ironstone Concretion)
Limonite (FeO(OH)·nH2O)
sedimentary
Man-made Metal Pin (Non-geological)
Antimony-Lead Alloy or Zinc/Brass Base with Electroplating
Metal Alloy / Manufactured Artifact
Chert (specifically Jasper or Brown Chert node)
Microcrystalline Quartz (SiO2)
sedimentary
Magnetite (Lodestone)
Magnetite (Fe3O4)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various additives
Man-made material (Anthropogenic 'mineraloid')
Thunderegg (Agate-filled Geode Node)
Silicon dioxide (SiO2) with various inclusions
sedimentary/igneous association
Corundum (Sapphire variant)
Aluminium oxide (Al2O3)
mineral
Basalt (River or Beach Pebble)
Basalt (Mafic Extrusive Igneous Rock)
igneous
Gossan (Limonite/Ironstone)
Hydrated Iron Oxide (FeO(OH)·nH2O)
sedimentary
Conglomerate
Sedimentary Conglomerate
sedimentary
Limonite Pseudomorph after Pyrite
Limonite (Hydrous iron oxides, FeO(OH)·nH2O) replacing Pyrite (FeS2)
mineral
Desert Varnish (on Sandstone)
Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)
sedimentary
Rutilated Quartz Sphere
Silicon Dioxide with Titanium Oxide inclusions (SiO2 with TiO2)
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Slag (Industrial Byproduct)
Anthropogenic Vitreous Silicate material
igneous
Green Sea Glass
Amorphous Silica (man-made glass), SiO2 + additive metal oxides
mineraloid / anthropogenic (man-made origin)
Pink Quartzite Pebble
Quartzite (SiO2)
metamorphic
Agate (Dyed Blue)
SiO2 (Silicon Dioxide)
Mineral (Chalcedony/Quartz variety)
Specular Hematite (Specularite)
Iron Oxide (Fe2O3)
mineral
Black Obsidian
Volcanic Glass (predominantly SiO2, Silicon Dioxide)
igneous
Amethyst
Quartz variety; SiO2 (Silicon Dioxide)
Mineral