Mineral Precipitate (Anthropogenic Context)

Gypsum crystal cluster (selenite/ satin-spar variety)

Gypsum — calcium sulfate dihydrate, CaSO₄·2H₂O

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Banded Agate

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Blue calcite (probable)

Calcite, calcium carbonate (CaCO₃)

Milky Quartz Vein with Matrix

Silicon Dioxide (SiO2)

Ocean Jasper

Orbicular Jasper (SiO2)

River Chalcedony / Agate

Chalcedony (Silicon Dioxide, SiO2)

Carnelian Agate

Carnelian (Silicon Dioxide - SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Orange calcite pieces on blue calcite or aragonite matrix

Calcite, CaCO₃; blue coloration likely trace-element-bearing calcite (possibly aragonite)

Yellow Jasper (Chert)

Silicon Dioxide (SiO2) with Iron Oxide impurities

Hematite

Iron(III) oxide (Fe2O3)

Orange Calcite

Calcium Carbonate (CaCO3)

Heulandite with Stilbite

Heulandite-Ca ((Ca,Na)2-3Al3(Al,Si)2Si13O36·12H2O) and Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Amethyst (Quartz)

Silicon Dioxide (SiO2) with Iron impurities

Druzy Quartz

Silicon Dioxide (SiO2)

Galena

Galena (lead sulfide, PbS), likely with associated sulfide minerals

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Jasper with Quartz Vein

Microcrystalline quartz (SiO2) with impurities

Quartz (Druzy) in host rock

SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)

Geode (unopened) or Calcareous Nodule

Siliceous or Calcareous Concretion/Nodule

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with marine fossils

Green Aventurine

Silicon Dioxide (Quartz variety with Fuchsite inclusions - SiO2)

Native copper nugget

Copper (Cu), commonly with cuprite and copper-oxide alteration

Red Jasper and Mookaite Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Quartz Vein Rock

Quartz (Silicon Dioxide, SiO2)

Calcite crystal cluster (dogtooth/saddle calcite)

Calcite — calcium carbonate, CaCO₃

Orange Calcite (Polished Sphere)

Calcium Carbonate (CaCO3)

Iron-rich breccia (likely hematite–goethite breccia)

Hematite (Fe₂O₃) and goethite (FeO(OH)) in a silicified or iron-cemented breccia

Blue calcite

Calcite (CaCO₃), likely blue calcite with white carbonate matrix

Polished blue calcite (likely)

Calcite, CaCO₃

Native copper nugget

Native copper (Cu)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with Iron impurities)

Carnelian (a variety of Chalcedony)

SiO2 (Silicon Dioxide) primarily colored by iron oxide (Hematite)

Moqui Marble (Concretion)

Iron Oxide Concretion

Larimar

Pectolite (NaCa2Si3O8(OH))

Clear Quartz (Rock Crystal) Bracelet

Silicon Dioxide (SiO2)

Fluorite (specifically Blue John or Banded Fluorite)

Calcium Fluoride (CaF2)

Onyx Marble (also commonly called Onyx)

Calcite (CaCO3), often with other mineral impurities

Quartzite Geode (unopened)

SiO2 (Silicon Dioxide)