Chert / Flint Nodule
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse man made composite (lithified equivalent of sedimentary) specimens identified by the Rock Identifier community.
Chert / Flint Nodule
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartz
Quartz (SiO₂)
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Aragonite Star Cluster (or Aragonite Sputnik)
Aragonite (Orthorhombic Calcium Carbonate, CaCO3)
Red Jasper
Jasper (Silicon Dioxide with iron oxide inclusions), SiO2
Conglomerate
Conglomerate (a clastic sedimentary rock)
Carnelian Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Red Jasper (with Quartz inclusions)
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
River Rock / Stream Pebble
Fluvial Clast / Rounded Sedimentary Particle
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
Jasper (Red/Yellow)
Silicon Dioxide (SiO2) with impurities
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Quartz
Quartz (SiO₂)
Ironstone (Limonitic Concretion)
Limonite (FeO(OH)·nH2O) with Goethite and Hematite inclusions
Quartz
Silicon Dioxide (SiO2)
Quartz (likely milky/rose quartz variety)
Quartz (SiO2 - Silicon Dioxide)
Chalcedony (Common Opal/Chert variety)
Silicon Dioxide (SiO2)
Synthetic Convention Badge (Plastic/PVC)
Polyvinyl Chloride (PVC) / Polycarbonate
Conglomerate
Conglomerate (a clastic sedimentary rock)
Gneiss
Gneiss (High-grade metamorphic rock)
Diamond (in Jewelry)
Carbon (C)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Banded Gneiss
Gneiss (Metamorphic high-grade rock)
Gneiss
Gneiss (High-grade regional metamorphic rock)
Veined Quartz
SiO2 (Silicon Dioxide)
White Quartz
Quartz (SiO2)
Green Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
Sandstone
Arenite (composed primarily of SiO2)
Sandstone (Pebble/Cobble)
Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Clear Quartz (Rock Crystal)
Quartz (SiO₂)
Rough Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Calcite
Calcite (Mineral; CaCO₃)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Quartz (Float/Abraded)
Quartz (SiO₂)
Pearl
Organic gemstone (Calcium carbonate - CaCO3)
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
Diamond
Diamond (pure Carbon, C)
Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)
Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)