Mineral Precipitate (Anthropogenic Context)

Scoria with Calcite Infills

Vesicular Basalt with secondary Calcification (CaCO3)

Kyanite in Quartz

Kyanite (Al2SiO5) with Quartz (SiO2)

Schist

Schist

Sandstone Pebble

Arenite (SiO2 principal)

Yellow Aventurine

Quartz (Silicon Dioxide) with Mica inclusions (SiO2)

Turquoise (likely stabilized or simulated Howlite)

CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)

Malachite

Cu2CO3(OH)2 (Copper Hydroxide Carbonate)

Limonite with Hematite

Hydrated iron(III) oxide-hydroxide with variable composition (FeO(OH)·nH2O)

Limonite with Trace Fossils

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

Limonite (Ironstone)

Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)

White Calcite

Calcium Carbonate (CaCO3)

Turquoise in Matrix

Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O

Limonite Concretion

Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O

Common Opal (Green Opal)

Hydrated Silicon Dioxide (SiO2·nH2O)

Tiger's Eye (Rough Slab)

Pseudomorph of Quartz after Crocidolite (SiO2 with Fe-containing inclusions)

Gneiss

Gneiss (quartz-feldspar-biotite gneiss)

Gneiss

Metamorphic rock of high-grade regional metamorphism

Quartz / Quartzite

Silicon Dioxide (SiO2)

Quartz Vein in Schist

Quartz (SiO2) in Pelitic Schist

Gold in Matrix

Native Gold (Au)

Biotite Schist (likely)

Biotite Schist (rock), Biotite (mineral)

Pyrite

Iron Sulfide (FeS2)

Lapis Lazuli

Lapis Lazuli (A complex rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Lapis Lazuli

A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).

Mica Schist with Quartz

Mica Schist (primarily Muscovite or Biotite with Quartz)

Fluorite

Calcium Fluoride (CaF2)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Snowflake Obsidian

Spherulitic Obsidian (primarily SiO2)

Calcite with Quartz coating

Calcium Carbonate (CaCO3) with Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Amethyst (Purple), Sulfur (Yellow), and Blue Apatite

SiO2 (Quartz), S (Native Sulfur), Ca5(PO4)3(F,Cl,OH) (Apatite Group)

Snowflake Obsidian

Obsidian with Cristobalite inclusions

Green Calcite

Calcite (Calcium Carbonate, CaCO3)

Bauxite

Bauxite (Mixture including Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH))

Bauxite

Bauxite (Mixture of Al(OH)3, AlO(OH), and Fe2O3)

Milky Quartz Pebble with Iron Inclusions

Silicon Dioxide (SiO2)

Banded Gneiss (with possible weathered sulfide or iron staining)

Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides

Milky Quartz (with Chlorite/Mineral Inclusions)

Silicon Dioxide (SiO2)

Native Copper

Native Copper (Cu)

Sandstone

Arenite (primarily SiO2)

Green Fluorite

Calcium Fluoride (CaF2)

Quartz (Granular Milky Quartz fragment)

Silicon Dioxide (SiO2)