Sandstone (with Iron concretions/staining)
Arenite (composed primarily of Quartz and Feldspar with Iron Oxide cement)
sedimentary
Category
Mineral (Occurring As A Rolled Clast)
Browse mineral (occurring as a rolled clast) specimens identified by the Rock Identifier community.
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
sedimentary
Chert (Lightly weathered variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Ironstone (Limonitic Concretion)
Limonite (FeO(OH)·nH2O) with Goethite and Hematite inclusions
sedimentary
Carnelian
Carnelian (SiO2 - Silicon Dioxide with Iron Oxide impurities)
mineral
Brecciated Jasper
Silicon Dioxide (SiO2) with varying mineral inclusions (Iron Oxide, Hematite, Clay)
sedimentary (clastic/chemical)
Pumice
Pumice (Amorphous volcanic glass)
Igneous
Obsidian
Volcanic Glass (SiO2)
igneous
Beaded Jewelry (Assorted Gemstones)
Various minerals, including but not limited to Quartz (SiO2), Garnet (X3Y2(SiO4)3), Jade (Na(Al,Fe)Si2O6), Amethyst (SiO2),等の多様な組み合わせ
Mineral, Jewelry
Selenite / Gypsum
Gypsum (CaSO4·2H2O)
Mineral
River Stone (likely Quartzite or Chert)
Recrystallized Silicon Dioxide (SiO2)
metamorphic
Chert (Cherty Limestone or Flint)
Microcrystalline Silica (SiO2)
sedimentary
Zircon
Zircon (ZrSiO4)
Mineral
Chert (Tan/Yellow variety)
Microcrystalline quartz (SiO2)
sedimentary
Granodiorite
Phaneritic intrusive igneous rock (Granodiorite)
igneous
Puddingstone (specifically Michigan/Gowganda Puddingstone)
Quartzite Conglomerate (Gowganda Formation)
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Red Jasper
Jasper (SiO2 with Fe2O3 inclusions)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Glass / Silicon Dioxide (Man-made)
SiO2 (Amorphous Silicon Dioxide)
Amorphous Solid
Chert (Hagstone/Gasket Rock variant)
Chert (SiO2)
sedimentary
Garden Quartz (Phantom Quartz)
Silicon Dioxide (SiO2) with various inclusions (often Chlorite, Hematite, or Iron)
mineral
Chert (Flint)
Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Labradorite
(Ca, Na)(Al, Si)4O8
mineral
Gold Nugget
Native Gold (Au)
mineral
Sandstone
Sandstone (clastic sedimentary rock)
Rock
Granite Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Amber (Cherry Amber)
Succinite (C10H16O)
Organic Gemstone
Tiger's Eye (likely variant or dark tumble)
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Magnetite
Magnetite (Fe3O4)
Mineral
Smoky Quartz
Smoky Quartz (SiO ₂)
Mineral
Chert (or Carnelian Agate)
Microcrystalline Quartz (SiO2)
sedimentary
Jasper-Agate Conglomerate (Potentially Puddingstone)
Jasper-cemented Silicate Aggregate (SiO2)
sedimentary
Chert (specifically Pink/Tan Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chrysocolla on Quartz/Rhyolite matrix
Hydrated copper phyllosilicate mineral: (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Jasper (specifically a banded or dark variety)
Silicon Dioxide (SiO2) with impurities
sedimentary
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Granodiorite Pebble
Granodiorite (Intermediate intrusive igneous rock)
igneous
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Metal Alloy (Likely Pewter or Sterling Silver)
Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).
Man-made material (metal)