Chert (Common Opal/Agate inclusion)
Microcrystalline Quartz (SiO2)
Category
Browse mineral (or mineraloid if microcrystalline) specimens identified by the Rock Identifier community.
Chert (Common Opal/Agate inclusion)
Microcrystalline Quartz (SiO2)
Shale
Fissile Mudstone
Ironstone Concretions (Ironstone)
Ferruginous Sandstone or Siltstone (Fe2O3)
Quartzite Pebble
Quartzite (primarily SiO2)
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Jasper with Quartz Druzy
Silicon Dioxide (SiO2)
Dalmatian Stone (Dalmatian Jasper)
Peralkaline Quartz-Feldspar Porphyry with Arfvedsonite
Chert (Arrowhead Preform or Flake)
Microcrystalline Quartz (SiO2)
Chert Pebble with Quartz Veining
Microcrystalline Quartz (SiO2)
Quartz-veined Sedimentary Rock
Hydrothermally veined Clastic Sedimentary Rock (SiO2 veins in Matrix)
Limonite Concretion
Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O
Chert Pebble (Jasper/Quartz variety)
Microcrystalline Quartz (SiO2)
Limonite
Limonite (FeOO·nH2O)
Agate (Carnelian-like)
Chalcedony (Silicon Dioxide, SiO2)
Limonite Concretion (Ironstone)
Limonite (FeO(OH)·nH2O) / Goethite
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Chert (vuggy variety)
Microcrystalline silica (SiO2)
Sardonyx Agate Sphere
Cryptocrystalline Quartz (SiO2) with iron oxide inclusions
Limonite (often after Hematite or Goethite)
Limonite (FeO(OH)·nH2O)
Argetine Blue Agate (Chalcendony variant)
Silicon Dioxide (SiO₂)
Bauxite
Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Chert Nodule (Fossiliferous Chert)
Microcrystalline Quartz (SiO2)
Moss Agate Geode Sphere
Silicon Dioxide (SiO2) - Chalcedony with Chlorite or Manganese inclusions
Blue Chalcedony
Silicon Dioxide (SiO2)
Carnelian
Carnelian (SiO2 with Iron Oxide impurities)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Limonite streaks)
Quartz Pebble (Water-worn Quartzite)
Silicon Dioxide (SiO2)
Agate (or Chalcedony)
Silicon Dioxide (SiO2)
Hag Stone
Perforated Sedimentary Rock
Shale
Lutaceous Sedimentary Rock
Tree Agate
Dendritic Chalcedony (SiO2)
Baroque Pearl
Biogenic Calcium Carbonate (Aragonite/Conchiolin)
Ocean Jasper
Orbicular Jasper (Silicon Dioxide, SiO2)
Chert (Flint) with Glauconite
Microcrystalline Quartz (SiO2)
Chert (Mudstone)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Septarian or Nodular variety)
Microcrystalline Quartz (SiO2)
Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite
Red Jasper
Silicon dioxide (SiO2) with iron oxide inclusions