Mineral, Organic Gemstone

Fossilized Bivalve Shell

Class Bivalvia (fossilized)

Chert (Jasper/Flint variant)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Petrified Wood

Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)

Septarian Nodule

Septarian Concretion (CaCO3 with Siderite/Limonite streaks)

Amber

Succinite (with a generalized formula of C10H16O)

Sandstone

Arenite (primarily SiO2)

Chalcedony (Chert/Flint)

Silicon Dioxide (SiO2)

Banded Calcite (Zebra Calcite)

Calcite (CaCO3) with trace organic or oxide inclusions

Jasper

Silicon dioxide (SiO2) with impurities

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Fossilized Bone

Petrified Bone (Fluorapatite / Calcium Phosphate replacement)

Moss Agate

Silicon Dioxide (SiO2) with mineral inclusions

Quartz Vein Rock

Silicon dioxide (SiO2) within a host rock matrix

Green Moss Agate

Agate (Silicon Dioxide, SiO2) with inclusions

Chert (Yellow/Brown Jasper)

Silicon Dioxide (SiO2)

Shark Tooth Fossil

Chondrichthyes (class) fossilized tooth

Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Petrified Wood

Silicified Wood (Permineralized wood)

Fossilized Bone

Permineralized Bone (Vertebrate Fossil)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (Jasper-rich)

Silicon Dioxide (SiO2)

Fossil Shark Tooth

Chondrichthyes (class); likely Lamniformes (order) fossilized in Apatite/Hydroxyapatite

Petrified Wood

Silicified Wood (SiO2)

Jasper

Silicon dioxide (SiO2) with impurities

Amber

Succinite (fossilized tree resin)

Chert (Jasper/Flint variant)

Microcrystalline quartz (SiO2)

Chert (and Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

Small greenish crystal/mineral fragment

Indeterminate; possibly olivine, quartz, or a green gemstone fragment

Moss Agate

Chalcedony (SiO2) with inclusions of hornblende or chlorite

Moss Agate

Chalcedony (Silicon Dioxide) with inclusions - SiO2

Dendritic Agate

Chalcedony (SiO2) with manganese/iron oxide inclusions

Fossilized Shark Tooth

Chondrichthyes (Class)

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Chert (Arrowhead/Artifact Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ironstone Concretion

Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)

Petrified Wood

Silicified Wood (SiO2)

Chert (Quartz Variety)

Microcrystalline Silica (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Fossiliferous Sandstone

Sedimentary rock containing invertebrate fossils

Jasper

Silicon dioxide (Quartz variety), SiO2

Fossilized bone fragment (probable mammalian tooth or bone)

Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite