Yellow Quartzite River Cobble
Meta-quartzite (SiO2 with iron oxide staining)
metamorphic
Category
Sedimentary (Imitation)
Browse sedimentary (imitation) specimens identified by the Rock Identifier community.
Granite (Dioritic or Hornblende-rich)
Phaneritic Plutonic Felsic to Intermediate Igneous Rock
igneous
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
mineral
Quartz (Milky/Iron-stained)
Silicon Dioxide (SiO2)
mineral
Orange Quartzite (River Pebble)
Quartzite (primarily SiO2)
metamorphic
Yellow Quartz Pebble (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
Honey Calcite Geode Segment
Calcite (Calcium Carbonate, CaCO3)
mineral
Fossilized Sea Urchin (Echinoid)
Echinoidea (Class); commonly Clypeasteroida for sand dollar types
sedimentary (fossil)
Limonite (often after Hematite or Goethite)
Limonite (FeO(OH)·nH2O)
mineral
Limonite (with Goethite/Ironstone)
FeO(OH)·nH2O (Hydrated Iron Oxide)
mineral
Druzy Quartz on Host Rock
Silicon Dioxide (SiO2)
mineral
Grey Slate
Foliated Metamorphic Rock (formed by low-grade regional metamorphism of shale or mudstone)
metamorphic
Dalmatian Stone
Peralkaline Feldsphathic Igneous Rock
igneous
Jasper (brecciated or orbicular variety)
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary/mineral
Chert (or Flint)
Chert (cryptocrystalline quartz), SiO2
Sedimentary
Black Opal
Hydrated Silica (SiO2·nH2O)
mineral
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated Iron Oxide)
mineral
Petrified Wood
Silicified Wood (primarily SiO2)
metamorphic
Puddingstone
Conglomerate (specifically a type of jasper conglomerate or quartz conglomerate)
Sedimentary
Leopardskin Jasper
Jasper (a variety of microcrystalline Quartz)
Sedimentary
River Stone / Pebble
Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)
Mineral, Sediment
Magnetite
Magnetite (Fe3O4)
Mineral
Quartz (likely) or a Quartzite Pebble
Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.
Mineral, specifically a detrital grain
Celestine (or Celestite) Geode
Strontium Sulfate (SrSO4)
mineral
Quartz (Clear Quartz)
Silicon Dioxide (SiO2)
mineral
Chert (Tan/Grey variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
mineral
Chert (Field-collected Arrowhead-shaped Fragment)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Green Jasper
Jasper (Silicates, SiO2)
sedimentary
Galena
Lead Sulfide (PbS)
mineral
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
mineral
Jasper with Dendritic Inclusions
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Agate
Silicon Dioxide (SiO2) - variety Chalcedony
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Pyrite (Fools Gold)
Iron Sulfide (FeS2)
mineral
Amethyst Geode
Silicon Dioxide (SiO2) with iron impurities
mineral
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Chalcedony (Botryoidal)
Silicon Dioxide (SiO2)
mineral