Chert (Siliceous Mudstone variant)
Microcrystalline quartz (SiO2)
Category
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
Chert (Siliceous Mudstone variant)
Microcrystalline quartz (SiO2)
Chert (Nodular)
Microcrystalline Silica (SiO2)
Amber
Succinite (a variety of fossilized tree resin); chemical formula appx. C10H16O
Chert
Chert (Microcrystalline Quartz, SiO2)
Glauconitic Sandstone
Glauconite-bearing Arenite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (with Quartz Druzy)
Microcrystalline Silica (SiO2)
Chert / Flint
Silicon dioxide (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Iron inclusions
Cultured pearls
Pearl; predominantly aragonite (CaCO₃) in nacre with organic conchiolin
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Amber
Succinate (Fossilized Resin)
White limestone or chalky carbonate rock
Calcite-rich limestone; possibly chalk (CaCO₃)
Petrified Wood
Silicified Wood (SiO2)
Green Chert (Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Amber
Succinite
Small yellow-orange mineral fragment, likely amber or iron-stained quartz
Possibly amber (fossilized resin; organic mineraloid) or quartz (SiO₂)
Picture Jasper
Silicon Dioxide (SiO2) - Opaque Chert/Quartzite variety
Glauconite (Greensand)
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Chert
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Translucent amber-colored gemstone, likely citrine or amber
Most plausibly quartz (SiO₂), specifically citrine; amber would be fossilized resin (organic polymer)
Jasper
Silicon Dioxide (SiO2)
Chert (Smooth River Pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert / Flint
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Jasper variety)
Silicon Dioxide (SiO2) with iron oxide impurities
Chert (Flint)
Chert (SiO2)
Chert (often called Flint)
Chert (Cryptocrystalline Silica, SiO2)
Chert (often called Flint when found in chalk)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Silicon Dioxide (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Limestone (River or Sea Cobble)
Calcium Carbonate (CaCO3)
Gravel / Limestone Fragment
Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock
Chert (often called Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert
Chert (Microcrystalline Quartz, SiO2)
Amber
Succinates (Organic Fossilized Resin)
Banded Chert / Sandstone Pebble
Microcrystalline Quartz (SiO2) / Silicified Sandstone
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Petrified Wood / Fossilized Bone
Silicified / Mineralized Fossil (Silica SiO2)