Flint
SiO2 (Cryptocrystalline Quartz)
sedimentary
Category
Anthropogenic (Man Made Material)
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Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Fossilized Coral (Petoskey Stone / Hexagonaria)
Hexagonaria percarinata / Rugosa coral (CaCO3)
fossil
Brecciated Jasper
Brecciated Jasper (Microcrystalline Quartz / SiO2)
sedimentary
Green Aventurine
Silicon Dioxide (SiO2+KAl2(AlSi3O10)(OH)2)
metamorphic
Gabbro
Gabbro (Mg, Fe)2Si2O6 / (Ca, Na)(Al, Si)4O8
igneous
Granite
Granite (composed primarily of Quartz, Feldspar, and Mica)
igneous
Chert (with Quartz)
Microcrystalline Quartz (SiO2)
sedimentary
Tumbled blue-green stone, likely chrysocolla or dyed chalcedony
Probable chrysocolla (hydrated copper aluminosilicate; variable composition), though appearance could also represent dyed chalcedony
mineral
Polished white chalcedony or milky quartz pebble
Chalcedony, microcrystalline quartz (SiO₂), possibly with iron-oxide staining or a minor mineral inclusion
mineral
Bog Iron / Limonite Concretion
Goethite/Limonite mixture (FeO(OH)·nH2O)
sedimentary
Turquoise
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
mineral
Petoskey Stone / Rugose Coral Fossil
Hexagonaria percarinata
fossil
Likely blue glass or synthetic gemstone jewelry
Uncertain; possibly synthetic spinel, cubic zirconia, or blue glass
gemstone
Fossil Coral
Scleractinia (Stony Coral) fossil
fossil
Mixed Gemstone Beaded Jewelry
Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)
Mineral
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)
Quartzite
Metamorphic Rock (Mainly SiO2)
metamorphic
Obsidian
Obsidian (volcanic glass, amorphous silica rich rock)
Igneous
Granite
Granite (Plutonic Igneous Rock)
igneous
Granite
Granite (Silicic Intrusive Igneous Rock)
Igneous
Granite
Granite (Felsic Plutonic Rock)
igneous
Granite
Granite (phaneritic intrusive igneous rock consisting of quartz, feldspar, and mica)
igneous
Sandstone
Arenite
sedimentary
Sandstone
Arenite (mostly SiO2)
sedimentary
Chert
Chert (microcrystalline quartz)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Flint
Silicon Dioxide (Microcrystalline Quartz, SiO2)
sedimentary
Flint / Chert
Microcrystalline quartz (SiO2)
sedimentary
Diamond
Carbon (C)
gemstone
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Banded Jasper / Chert Beach Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Brecciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Smoky Quartz
Smoky Quartz (SiO2)
mineral
Pearl
Organic gemstone (Calcium carbonate - CaCO3)
mineral
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
mineraloid
Diamond (in a jewelry setting)
Cubic Carbon (C)
mineral
Obsidian
Volcanic Glass (SiO2)
igneous
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
igneous
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary