Jasper
Microcrystalline quartz (SiO2)
sedimentary
Category
Mineraloid (Human Made Geological Specimen)
Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.
Pyrite in Quartz
Iron Sulfide (FeS2) embedded in Silicon Dioxide (SiO2)
mineral
Fossiliferous Shale
Sedimentary Clastic Rock with fossil inclusions (likely Brachiopod or Bivalve impressions)
fossil
Quartz Vein in Sedimentary Matrix
Silicon Dioxide (SiO2) with host rock
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Sea Glass
Amorphous Silica (Glass) SiO2
Mineraloid (Man-made origin)
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
River Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Banded Onyx (Calcite Marble)
Calcite (CaCO3) - Trap-rock or Cave Onyx
sedimentary
Quartz / Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz-veined Basalt or Limestone Pebble
Quartz vein in host rock (Silicate mineral in carbonate or volcanic matrix)
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Sandstone (Ferruginous)
Arenite (SiO2 with Fe-oxide cement)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Fossilized Gastropod in Limestone
Gastropoda (Class) in Fossiliferous Limestone
sedimentary
Fossiliferous Limestone with Rugose Coral
Calcium Carbonate (CaCO3) featuring Rugosa (extinct order of solitary and colony corals)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
mineral
Small rounded pebble, likely quartz-rich stone
Indeterminate from photograph; possibly microcrystalline quartz (SiO₂) or a weathered silicate pebble
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Tumbled/Water-worn pebble)
Silicon Dioxide (SiO2)
mineral
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Slate
Metamorphic Pelitic Rock
metamorphic
Pink quartz-rich stone, likely rose quartz
Rose quartz; quartz, SiO₂, commonly colored by trace elements and microscopic inclusions
mineral
Mahogany Obsidian
Volcanic Glass (SiO2 with Fe/Mg oxides)
igneous
Glacial erratic boulder
Likely weathered sandstone or quartzitic sandstone; exact identification requires a fresh surface and locality
sedimentary
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Halite
Halite (Sodium Chloride - NaCl)
Mineral
Quartz Cobble (River Pebble)
Quartz (Silicon Dioxide - SiO2)
mineral
Weathered iron-rich sandstone or ironstone
Ferruginous sandstone, likely limonite/goethite-cemented quartz arenite
sedimentary
Amethyst Cluster
Silicon Dioxide (SiO2 with iron impurities)
mineral
Amygdaloidal Basalt with Quartz Infill
Amygdaloidal Basalt (SiO2 infill)
igneous
Goethite / Limonite Gossan
Hydrated Iron Oxide (FeO(OH))
sedimentary
Amygdaloidal Basalt with Epidote
Vesicular Basalt with secondary Epidote/Quartz mineral infill
igneous
Green Chert
Microcrystalline Quartz (SiO2)
sedimentary
Limonite (with goethite)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
mineral
Biotite Schist
Biotite Schist (Rich in K(Mg,Fe)3AlSi3O10(OH)2)
metamorphic
Banded Calcite (often commercially called 'Mexican Onyx')
Calcium Carbonate (CaCO3)
mineral
Moqui Marble (Ironstone Concretion)
Iron Oxide Concretion (Fe2O3 / FeO(OH))
sedimentary