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)
Category
Browse sedimentary (alluvial deposit) specimens identified by the Rock Identifier community.
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)
Laterite
Laterite (no specific mineral formula as it's a rock type)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Diamond
Diamond (pure carbon; C)
Thunderegg (Agate-filled Geode Node)
Silicon dioxide (SiO2) with various inclusions
Sandstone (likely a river or beach pebble)
Sandstone (a clastic sedimentary rock)
River Pebble (Likely Chert or Fine-Grained Sandstone/Quartzite)
Siliciclastic clast (likely Chert or Quartzarenite/Quartzite pebble)
Chert (Jasper or Flint variant)
Chert (composed of microcrystalline quartz, SiO2)
Quartz (likely Milky Quartz or Chalcedony)
Quartz (SiO2 - Silicon Dioxide)
Chert (or possibly Flint)
SiO2 (Silicon Dioxide)
Quartz (pebble)
Quartz (SiO₂)
Veined Pebble (likely a Quartz-Veined Pebble)
Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Handaxe with Inlaid Fossil Echinoid
Flint / Chert (SiO2) containing a fossil Conulus albogalerus
Red Jasper (River Pebble)
Silicon Dioxide (SiO2) with hematite impurities
Chert (often referred to as 'Jasper' when red)
Chert (microcrystalline quartz, SiO₂)
Calcite
Calcite (CaCO₃, Calcium Carbonate)
River Pebbles (Stream-rounded rocks)
Fluvial Detritus (varied mineralogy)
Hematite (beads)
Hematite (Fe₂O₃)
Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)
Quartz (SiO₂)
Cherry Creek Jasper (also known as Red Creek Jasper or Cherry Creek Agate)
Jasper, microcrystalline quartz (SiO₂)
Calcite
Calcite (CaCO₃)
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Ocean Jasper
Silicon Dioxide (SiO2)
Gossan with Copper Carbonate (Chrysocolla/Malachite)
Ferruginous Oxide (Gossan) with Cu2CO3(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Limonite (Iron Ore)
Hydrous Iron Oxide (goethite, lepidocrocite)
Jasper with Hematite (Red Jasper)
Silicon Dioxide with Iron Oxide (SiO2 and Fe2O3)
Sandstone
Arenite (general term for sandstone)
Limonite (Iron Ore/Hydrated Iron Oxide)
Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))
Amber
Succinite (fossilized tree resin)
Green Aventurine and Clear Quartz
Aventurine (variety of Quartz - SiO2) and Quartz (SiO2)
Amber (Black)
Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)
Puddingstone (Jasper Conglomerate)
Conglomerate (specific type: Jasper Conglomerate or Hertfordshire Puddingstone)
Kyanite
Kyanite (Al2SiO5)
Labradorite (a variety of Feldspar)
Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Quartz (Milky Quartz)
Quartz (SiO2 - Silicon Dioxide)
Pyrite
Pyrite (Iron sulfide, FeS₂)
Flint
Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)
Agate
Agate (a variety of Chalcedony, SiO2)
Carnelian
Carnelian (a variety of Chalcedony, SiO2)