Organic Mineraloid And Mineral

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Calligraphy Stone

Fossiliferous Limestone (containing Hematite and Shells)

Seashell Fossil

Gastropoda fossil

Petrified Wood

Silicified Wood (primarily SiO2)

Jasper

Silicon dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (often called Flint)

Microcrystalline to cryptocrystalline quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Fossiliferous Flint

Microcrystalline Quartz (SiO2) with Echinoid Fossil

Quartz pebble or seed/crumb

SiO2 (if quartz)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified wood (primarily Quartz, SiO2)

Fossilized Fish Skeleton in Matrix

Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices

Petrified Dinosaur Bone (Gembone)

Agatized Dinosaur Bone

Jasper

Silicon dioxide (SiO2)

Amber (possibly a small polished amber cabochon)

Fossilized tree resin; amber is an organic gemstone, not a mineral

Amber

Succinicum (Organic polymer, largely C10H16O)

Amber

Succinite

Graphite-bearing schist (probable)

Graphite schist; chiefly quartz, mica, and graphite

Concretion (likely iron-rich sandstone or claystone concretion)

Diagenetic carbonate/iron-oxide concretion; exact mineralogy requires testing

Amber

Succinite (fossilized tree resin)

Concrete or asphalt-like aggregate surface with a dark fragment

Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock

Amber (in Matrix/Shale)

Amber (Fossilized Tree Resin)

Shungite

Non-crystalline carbon (C)

Jasper Agate

Silicon dioxide (SiO2)

Precious Red Coral

Corallium rubrum (Calcium Carbonate, CaCO3)

Chalcedony (Common Opal variant)

Silicon dioxide (SiO2) with varying levels of hydration

Honey calcite (likely)

Calcite, calcium carbonate (CaCO₃)

Dendritic Agate (Tree Agate)

Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions

Green Moss Agate

Agate (Silicon Dioxide - SiO2) with inclusions of hornblende or chlorite

Tree Agate (or Moss Agate)

Dendritic Agate (Silicon Dioxide - SiO2)

Moss Agate and Hematite

Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)

Petrified Wood

Silicified wood (primarily SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Moss Agate

Chalcedony (SiO2) with inclusions of manganese or iron oxide

Chert

Chert (Microcrystalline Quartz, SiO2)

Turquoise and Red Coral

Turquoise: CuAl6(PO4)4(OH)8·4H2O; Red Coral: Corallium rubrum (organic gemstone)

Petrified Wood

Silicified Wood (SiO2)

Sandstone

Arenicola (comprising mostly Quartz, SiO2)

Coprolite

Fossilized Feces