Sedimentary Or Igneous Associated Mineral

Pyrite (on Quartz/Host Rock)

Iron Sulfide (FeS₂)

Tiger's Eye (Multicolor/Variegated)

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxides)

Carnelian Agate

Chalcedony (SiO2) with iron oxide inclusions

Green Apophyllite on Stilbite

Fluorapophyllite-(K) [(KCa4Si8O20F)·8H2O] and Stilbite [NaCa4(Si27Al9)O72·28H2O]

Beryllonite

Beryllonite (NaBePO4)

Azurite

Azurite (Cu3(CO3)2(OH)2)

Pyrite and Fluorite on Quartz (Matrix Specimen)

Iron Disulfide (FeS2) and Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)

Gneiss

Gneissic Metamorphic Rock (Mineral composition: Quartz, Feldspar, Amphibole/Biotite)

Pyrite

Iron Disulfide (FeS2)

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Clear Quartz

Silicon Dioxide (SiO2)

Blue Calcite

Calcium Carbonate (CaCO3)

Quartz Vein in Host Rock

Quartz (SiO2) in Mafic or Sedimentary Matrix

Slate

Slate (foliated metamorphic rock rich in quartz, sericite, and chlorite)

Gneiss (Banded Gneiss)

Gneiss

Clear Quartz

Crystalline Silicon Dioxide (SiO2)

Gneiss

Gneiss (High-grade Metamorphic Rock)

Silver (Jewelry Specimen)

Native Silver (Ag)

Sandstone (Red)

Arenite (primarily Quartz, SiO2, with Iron Oxide cement)

Quartz (Milky/Smoky variety on matrix)

Silicon Dioxide (SiO2)

Stichtite (often found in Serpentinite)

Stichtite Mg6Cr2CO3(OH)16·4H2O

Rhodonite

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

Pyrope Garnet (Bohemian Garnets)

Pyrope (from the group Mg3Al2(SiO4)3)

Gold

Native Gold (Au)

Gold

Gold (Native Au)

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)

Botryoidal Hematite (Iron Ore)

Iron(III) oxide (Fe2O3)

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)

Quartz (SiO₂)

Pebble

Clast (specifically a granule or small pebble)

Common Opal in Host Rock

Hydrated Silica (SiO2·nH2O)

Clear Quartz Crystal

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Chalcedony (Agate/Blue Quartzite)

Silicon Dioxide (SiO2)

Rough Precious Opal

Hydrated Silica (SiO2·nH2O)

Chalcedony (River Stone)

Microcrystalline Quartz (SiO2)

Chalcedony

Cryptocrystalline Quartz (SiO2)

Quartz (Milky/Clear)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Quartz (Milky/Chalcedony variety)

Silicon Dioxide (SiO2)

Gneiss

Gneiss

Gneiss

Gneiss