Sedimentary Or Igneous (Host Environment)

Chalcedony on Matrix

Silicon Dioxide (SiO2)

Milky Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Sandstone with Ironstone Concretion

Arenite with Hematite/Goethite nodules (Fe2O3 / FeO(OH))

Native Copper in Basalt

Cuprum (with Host Basalt)

Quartz Druze on Matrix (Geode Fragment)

Quartz (Silicon Dioxide, SiO2)

Sandstone Concretion

Sedimentary concretion

Gneiss with Quartz Veining

Gneiss (High-grade regional metamorphic rock)

Pyrite on Limestone

Iron Disulfide (FeS2) in Calcium Carbonate (CaCO3) matrix

Quartz Vein in Sandstone

Quartz (SiO2) in Clastic Sedimentary Rock

Quartz (Milky Quartz)

Silicon Dioxide (SiO₂)

Water and Silt (Sedimentary Environment)

Suspended Sediment / H2O (dihydrogen monoxide)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Pyrite in Shale

Iron Disulfide (FeS2) in Argillaceous Shale

Limestone (Brecciated/Recrystallized)

Calcium Carbonate (CaCO3)

Hag Stone

Naturally holed stone (typically sedimentary rock such as flint, limestone, or sandstone)

Pyritic Gneiss

Metamorphic Gneiss with Pyrite inclusions

Limestone

Calcium Carbonate (CaCO3)

Chrome Diopside

Magnesium Calcium Silicate (MgCaSi2O6) containing Chromium impurities

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Limestone (Grey and White specimens)

Calcium Carbonate (CaCO3)

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Veined Limestone (Micrite) with Quartz/Calcite Veins

Calcium Carbonate (CaCO3) with Silicate or Carbonate inclusions

Biotite Mica

Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)

Jasper or Agate pendant

Silicon dioxide (SiO2)

Druzy Quartz on Host Rock

Silicon Dioxide (SiO2) with various iron-oxide inclusions

Vuggy Quartz on Matrix

Crystalline Silicon Dioxide (SiO2)

Rock Crystal Quartz

Quartz (SiO₂)

Quartz Vein in Siltstone

Siltstone with Quartz (SiO2) inclusion

Rough Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Ruby

Corundum (Aluminium Oxide with Chromium impurities, Al2O3:Cr)

Chert (White Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ruby (Pink to Red Corundum)

Al2O3 (Corundum with Chromium impurities)

Quartz (Citrine or Iron-Stained variety)

Silicon Dioxide (SiO2)

Chert (Septarian Nodules / Weathered Silex)

Microcrystalline Quartz (SiO2)

Turquoise in Matrix

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

Glauconitic Sandstone

Glauconitic arenite (contains (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)

K2 Jasper (K2 Granite)

Azurite in Granite (Al2Cu3(CO3)2(OH)2 in NaAlSi3O8)

Druzy Quartz on Ironstone

Silicon Dioxide (SiO2) on Limonitic Ironstone

Gneiss (with Mica and Quartz)

Gneissic Metamorphic Rock

Chert (Flint nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Banded Agate (specifically Carnelian Agate slice)

Chalcedony (cryptocrystalline variety of Quartz), SiO2

Chalcedony in Host Rock

Chalcedony (SiO2)