Quartz-rich conglomeratic sandstone
Lithic arkose/conglomerate, dominated by quartz and feldspar grains
sedimentary
Category
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Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Mineral (or mineraloid if microcrystalline)
Seashell Fragment
Calcium carbonate (CaCO3) - primarily Aragonite or Calcite
fossil
Diamond (or Diamond Simulant)
Carbon (C) or Cubic Zirconia (ZrO2)
gemstone
Chert (Flint)
Silicon dioxide (SiO2)
sedimentary
Coquina
Bioclastic Limestone
sedimentary
Diamond (Cut Gemstone)
Carbon (C)
gemstone
Sandstone Concretion
Sedimentary Concretion (Quartz sand bound by mineral cement)
sedimentary
White Jade (Nephrite)
Nephrite, Ca2(Mg,Fe)5Si8O22(OH)2
Mineral
Agate
Silicon dioxide (Chalcedony), SiO2
gemstone
Agate
SiO2
mineral
Gold Nugget
Gold (Au)
mineral
Rhodochrosite
Rhodochrosite (MnCO3)
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Limestone
CaCO3 (principally composed of Calcite)
sedimentary
Crinoid Stem Fossil
Crinoidea (Class) / Calcite (CaCO3)
fossil
Celestite
Celestine (SrSO4)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Orange Calcite (Banded Honey Calcite)
Calcium Carbonate (CaCO3)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide)
igneous
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Stichtite in Serpentine (Atlantisite)
Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)
metamorphic
Diamond
Diamond (pure Carbon, C)
mineral
Rose Quartz Carving
Quartum roseum (Variety of Quartz, SiO2)
Mineral
Fossiliferous Limestone
Limestone (composed primarily of calcite with included fossils CaCO3)
Sedimentary
Fluorite
Calcium Fluoride (CaF2)
mineral
Rhodochrosite
Manganese Carbonate (MnCO3)
mineral
Rhodochrosite
Manganese Carbonate (MnCO3)
mineral
Howlite
Howlite (Calcium borosilicate hydroxide: Ca2B5SiO9(OH)5)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Granodiorite
Phaneritic Plutonic Intermediate-Felsic Rock
igneous
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Quartz in Matrix (Lepidolite or Quartzite)
Silicon Dioxide (SiO2) with host rock
mineral
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Pink Quartz
Silicon Dioxide (SiO2)
mineral
Quartz with Tourmaline or Amphibole
Silicon Dioxide with silicate inclusions (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary