Mineral (Impactite)

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

River Cobble (Quartz-rich Sandstone)

Arenite with iron oxide staining

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Green Tourmaline (Verdelite) / Actinolite

Tourmaline group: Na(Mg,Fe,Li,Al,Mn)3Al6(BO3)3Si6O18(OH)4 / Actinolite: Ca2(Mg,Fe)5Si8O22(OH)2

Malachite

Copper Carbonate Hydroxide (Cu2CO3(OH)2)

Chalcopyrite

Copper iron sulfide (CuFeS2)

Chiastolite (Andalusite)

Al2SiO5

Granite

Intrusive Igneous Rock

Porphyritic Igneous Rock with Iron Oxide Weathering

Weathered Porphyry (containing Quartz, Feldspar, Amphibole/Biotite, and Hematite/Limonite)

Likely serpentinized ultramafic rock (serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, possibly with magnetite, chromite, and brucite

Granodiorite

Granodiorite (Intermediate intrusive igneous rock)

Banded gneiss pebble

Biotite–quartz–feldspar gneiss (composition variable)

Native Copper in Basalt

Cu

Limonite or Ironstone Nodule

Hydrated iron oxide-hydroxide (FeO(OH)·nH2O)

Mixed polished rock/mineral specimens

Indeterminate from image; likely quartz-bearing material with iron-oxide staining and possibly mica-rich schist

Snowflake Obsidian

Volcanic Glass with Cristobalite Inclusions

Limonite Concretion

FeO(OH)qnH2O (Hydrated iron(III) oxide-hydroxide mixture)

Hematite

Hematite (Fe2O3)

Veined Pebble (Quartz/Calcite Veined Metamorphic/Sedimentary Rock)

Quartz / Calcite Veined Fault Breccia or Metamorphic Pebble

Fluorite

Calcium Fluoride (CaF2)

Vesicular basalt

Basalt, a mafic volcanic rock composed mainly of plagioclase feldspar, pyroxene, and often olivine

Greenstone

Protolith of basalt, diabase, or gabbro; often contains minerals like chlorite, actinolite, and epidote

Pale green translucent mineral fragment

Indeterminate; possibly fluorite, calcite, or glassy quartz

Calcite

Calcite (Mineral, Calcium Carbonate - CaCO3)

Pyrite

Iron Sulfide (FeS2)

Muscovite Mica

KAl2(AlSi3O10)(F,OH)2

Magnetite

Magnetite (Fe3O4)

Muscovite Mica

KAl2(AlSi3O10)(OH)2

Calcite

Calcium Carbonate (CaCO3)

Lepidolite

K(Li,Al)3(Si,Al)4O10(F,OH)2

Pyrite

Iron Sulfide (FeS2)

Barite

Barium Sulfate (BaSO4)

Calcite

Calcium Carbonate (CaCO3)

Quartz with Iron Oxide Inclusions

Silicon Dioxide (SiO2) with Iron Hydroxide/Oxide (Limonite/Goethite)

Quartzite with Schist layers

Metamorphosed Quartz-rich Rock (Mixed Schist/Quartzite)

Fuchsite

Cr-bearing Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Smoky Quartz with Rutile Inclusions

Silicon Dioxide (SiO2) with TiO2 needles

Quartz in Matrix (Lepidolite or Quartzite)

Silicon Dioxide (SiO2) with host rock

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Quartz with Tourmaline inclusions

Silicon Dioxide (SiO2) with Tourmaline needles