Likely ironstone or weathered chert with an iron-oxide spot
Silicified sedimentary rock, possibly ferruginous chert (microcrystalline SiO₂ with Fe oxides)
sedimentary
Category
Sedimentary (Secondary Mineral Formation)
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Weathered Sedimentary Rock with Liesegang Rings
Sandstone or Siltstone with Iron Oxide Banding
sedimentary
Chalcedony (Agate)
Silicon Dioxide (SiO2)
mineral
Hematite
Iron(III) oxide (Fe2O3)
mineral
Agate (Grey Agate Slice)
Microcrystalline Quartz (SiO2)
mineral
Banded Iron Formation (BIF) / Banded Sandstone Nodule
Hematite-rich Sandstone / Ferruginous Chert
sedimentary
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Sulfur
Native Sulfur (S8)
mineral
Ironstone Matrix with Jasper / Chert
Ferruginous Chert / Limonitic Jasper (SiO2 with Fe-oxides)
sedimentary
Carnelian
SiO2 (Silicon Dioxide, variety of Chalcedony)
mineral
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
sedimentary
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Granite / Diorite (Granitic Pebble)
Intrusive Felsic/Intermediate Igneous Rock
igneous
Hematite
Iron(III) oxide (Fe2O3)
mineral
Calcite
Calcite (CaCO₃, Calcium Carbonate)
Mineral
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
mineral
Malachite
Cu2CO3(OH)2 (Copper carbonate hydroxide)
mineral
Blue-green mineral specimen, likely chrysocolla or turquoise
Chrysocolla: hydrated copper phyllosilicate, approximately Cu₂H₂O₅Si; Turquoise: CuAl₆(PO₄)₄(OH)₈·4H₂O
mineral
Carnelian Agate
Chalcedony (Silicon Dioxide, SiO2)
mineral
Botryoidal hematite (ironstone)
Hematite, Fe₂O₃
mineral
Gold Nugget
Native Gold (Au)
mineral
Blue Agate (Dyed)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Limonite / Ironstone
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
mineral
Botryoidal limonite/goethite nodule
Limonite (largely goethite, FeO(OH), with hydrated iron oxides)
mineral
Agate (translucent water-worn pebble)
Cryptocrystalline Quartz (SiO2)
sedimentary
Jasper or Chert with Quartz Vugs
Silicon Dioxide (SiO2)
sedimentary
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O
mineral
Jasper (or possibly Agate/Chalcedony) beads
SiO2 (Silicon Dioxide)
mineral
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Iron-stained Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Specular Hematite (Specularite) in Matrix
Specularite (Fe2O3)
mineral
Banded Agate (with Quartz Geode Center)
Silicon Dioxide (SiO2)
mineral
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
mineral
Gold Nugget
Native Gold (Au)
mineral
Diamond Druzy (Crystalline Diamond)
Carbon (C)
mineral
Gold Nugget
Native Gold (Au)
mineral
Chert (with Quartz vein)
Chert (Silicon Dioxide, SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
sedimentary
Seashell (Calcium Carbonate)
Calcium Carbonate (CaCO3)
mineral
Weathered jasper-rich ironstone
Brecciated jasper/chert with iron oxides and hydroxides (SiO₂ with hematite, goethite, and limonite)
sedimentary
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral