Chert (with Quartz veins)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Chert (with Quartz veins)
Microcrystalline Quartz (SiO2)
Yellow Chert
Microcrystalline Quartz (SiO2)
Red Chert (Jasper)
Silicon Dioxide (SiO2)
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 principal component)
Turquoise, Pearl, and Coral Necklace
CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)
Chert (variations include Flint)
Sedimentary cryptocrystalline quartz (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Paleoxylon (SiO2)
Tree Agate (also known as Dendritic Agate)
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Weathered River Rock (likely Chert or Basalt with algae)
Silicon dioxide (SiO2) with organic biofilm
Yellow Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2) with iron oxide (Limonite/Goethite) inclusions
Fossilized Rugose Coral in Limestone
Order Rugosa in Sedimentary Matrix (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Shale or Siltstone
Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Limonite streaks)
Red Jasper
Quartz (SiO2) with iron oxide inclusions
Chert (Flint)
Silicon Dioxide (SiO2)
Jasper
Silicon Dioxide (SiO2) with impurities
Chert with Quartz Veining
Microcrystalline silica (SiO2)
Tumbled brown jasper (likely common jasper or chert)
Microcrystalline quartz, SiO₂, chiefly chalcedony/quartz with iron-oxide impurities
Chert (Flint)
Chert (Cryptocrystalline Silica, SiO2)
Chert (Gravel)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Pearl jewelry
Pearl (biogenic calcium carbonate, primarily aragonite, CaCO₃)
Petrified Wood
Silicified Wood (primarily Quartz/SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Fossiliferous Sandstone / Mudstone
Sedimentary Rock (Clastic with Fossiliferous Inclusions)
Limestone with Lichen
Carbonate Sedimentary Rock (primarily CaCO3)
White limestone or chalky carbonate rock
Calcite-rich limestone; possibly chalk (CaCO₃)
Travertine
Terrestrial Sedimentary Limestone (CaCO3)
Yellow Jasper / Chert
Jasper (Silica/Quartz) - SiO2
Banded Chert
Microcrystalline Quartz (SiO2)
Chert (often called Flint or Jasper)
Cryptocrystalline quartz (SiO2)
Chert (White Chert or Flint)
Microcrystalline or cryptocrystalline quartz (SiO2)
Fossilized Bone
Permineralized Bone (Vertebrate Fossil)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (specifically Red Chert / Jasper)
Silicon Dioxide (SiO2)
Chert / Chalcedony Nodules
Microcrystalline Quartz (SiO2)
Limestone
Calcareous sedimentary rock (CaCO3)
Banded Agate (Dyed)
SiO2 (Silicon Dioxide / Microcrystalline Quartz)