Marble

Belemnoit Fossil (Sea Squid Fossil)

Belemnitida (Order within Cephalopoda)

Ammonite Fossil

Ammonoidea (Calcium carbonate - CaCO3)

Pearl

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Chert (Pink variety/Jasper)

Silicon Dioxide (SiO2)

Gastropod Fossil (Internal Mold)

Phylum Mollusca, Class Gastropoda (Steinkern)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Pearl

Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)

Oolitic Limestone

Oolite (Sedimentary rock composed of CaCO3)

Fossiliferous Shale Matrix

Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments

Oolitic Limestone (Oolite)

Oolitic Limestone (primarily Calcium Carbonate, CaCO3)

Fossilized Pycnodonte Oyster

Pycnodonte (Gryphaeostrea) species; Composition is Calcium Carbonate (Calcite/Aragonite)

Shale

Fissile Mudstone (primarily composed of clay minerals and quartz)

Fossil Coral

Coral Limestone (a type of biogenic sedimentary rock)

Cockle Shell (Fossil or Recent)

Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)

Bivalve Shell (Fossil or Contemporary)

Class Bivalvie (various genera and species of clams, cockles, etc.)

Belemnite Fossil

Belemnitida (Order of extinct cephalopods)

Shale

Fissile mudstone (Shale)

Limestone

Calcium Carbonate (CaCO3)

Pearl

Aragonite and Calcite (CaCO3) with Conchiolin

Moissanite

Silicon Carbide (SiC)

Sandstone (Banded Sandstone)

Clastic Sedimentary Rock (primarily SiO2 with iron oxide impurities)

Limestone

Calcium Carbonate (CaCO3)

Olivine in Basalt matrix

Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)

Glauconitic Sandstone (Greensand)

Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)

Olivine (Peridot)

Olivine (Mg, Fe)2SiO4

Glauconite (Glauconitic Sandstone)

Glauconite [(K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2]

Orthoceras Fossil in Limestone

Orthoceras regulare (Class Cephalopoda; Order Orthocerida)

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Belemnite (Fossilized Rostrum)

Belemnitida (Order), composed of Calcite (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Fossil Coral (Honeycomb Coral)

Favosites (extinct genus of Tabulate coral)

Peridotite (Olivine)

Peridotite (comprising (Mg,Fe)2SiO4)

Limestone

Calcium Carbonate (CaCO3)

Limonite with Trace Fossils

Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)

Natural White Pearl

Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3

Glauconitic Sandstone

Glauconitic Sandstone (contains (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)

Olivine (in Peridotite/Dunite form)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Olivine (Peridotite)

Magnesium Iron Silicate - (Mg, Fe)2SiO4

Olivine/Peridot

Magnesium Iron Silicate (Mg,Fe)2SiO4

Olivine (Peridotite)

(Mg,Fe)2SiO4 (Magnesium Iron Silicate)