Synthetic Polymer (Polylactic Acid)

Azurite-Malachite with Limonite

Cu3(CO3)2(OH)2 (Azurite) / Cu2CO3(OH)2 (Malachite)

Limestone Breccia

Sedimentary Breccia (Calcareous)

Unakite / Epidosite

Epidote with Orthoclase and Quartz; (Ca2(Al2,Fe)(SiO4)3(OH)) / (KAlSi3O8) / (SiO2)

River Cobble (likely Quartzite or Limestone)

SiO2 (Quartzite dominant) or CaCO3 (Limestone dominant)

Limestone

Calcium Carbonate (CaCO3)

Prehnite

Prehnite, Ca2Al2Si3O10(OH)2

Aquamarine

Beryl (Be3Al2Si6O18), specifically the blue-green variety

Kidney Stone

Calcium Oxalate (CaC2O4), Uric Acid, or Struvite

Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (primarily CaCO3 as Calcite or Aragonite)

Sandstone (River Pebble)

Arenite (SiO2 based)

Pink Granite

Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Coquina

Coquina (Biogenic Limestone / CaCO3)

Aragonite (Star Cluster or Twinned variety)

Aragonite (Calcium Carbonate, CaCO3)

Orange Calcite

Calcium Carbonate (CaCO3)

Quartzite (Milky)

Metamorphic rock predominantly composed of Quartz (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Lapis Lazuli

Lapis lazuli (Mainly Lazurite: Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Coquina or Fossiliferous Limestone

Fossiliferous Calcarenite (CaCO3)

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Yellow Quartzite (Citrine-colored Quartz)

Silicon Dioxide (SiO2)

Marble

Recrystallized Calcite (CaCO3) or Dolomite (CaMg(CO3)2)

Honey Calcite

Calcium Carbonate (CaCO3)

Quartzite

Quartzite (SiO2)

Celestine (or Celestite)

Strontium sulfate (SrSO4)

Tufa (Vesicular Limestone)

Tufa (form of Calcium Carbonate, CaCO3)

White Marble (Industrial/Architectural)

Recrystallized Calcite (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Quartzite Cobble

Meta-quartzite (SiO2)

Sandstone (likely Arkosic or Lithic)

Clastic Sedimentary Rock (SiO2 with accessory minerals)

Rhodonite with Manganese Oxides

Rhodonite (Mn,Fe,Mg,Ca)SiO3

Marble

Metamorphosed Limestone (calcite formulation CaCO3)

Quartzite Pebble

Quartzite (SiO2)

Quartzite

Quartzite (SiO2)

Green Quartz (Prasiolite variant or Aventurine)

Silicon Dioxide (SiO2)

Blue Calcite

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Quartzite with Quartz Geode / Vug

Crystalline Silicon Dioxide (SiO2) in Metamorphic Host

Basalt with Quartz/Calcite Vein

Amygdaloidal Basalt (matrix) with Mineral Vein filling

Limestone

Calcium Carbonate (CaCO3)

Pink Banded Onyx (Mexican Onyx / Calcite)

Calcite (CaCO3) - microcrystalline calcium carbonate