Mineral, Often Found As A Rock (Metamorphic)

Almandine Garnet

Iron aluminum silicate (Fe3Al2(SiO4)3)

Coarse Sand Grain / Lithic Fragment

Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)

Greenstone / Greenschist

Chlorite schist / Epidiorite

Green Calcite

Calcium Carbonate (CaCO3)

Green Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Schist

Mica Schist

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Marble

Metamorphosed Limestone/Dolomite

Gneiss Pebble

Gneiss

Gneiss

Foliated Metamorphic Gneiss

Granite

Granite (Felsic Plutonic Rock)

Biotite on Matrix

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

Red Aventurine

Aventurine Quartz (SiO2 + Hematite/Goethite)

Clear Quartz

Silicon Dioxide (SiO2)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Orca Agate (Blue Chalcedony)

Silicon Dioxide (SiO2)

Epidote in Matrix (likely Amphibolite or Gneiss)

Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)) in Metamorphic Matrix

Serpentine

Antigorite, Lizardite, or Chrysotile (Mg, Fe)3Si2O5(OH)4

Pyrite

Iron Sulfide (FeS2)

Marble

Recrystallized Calcite (CaCO3)

Shale

Fissile mudrock (composed primarily of clay minerals and quartz)

White Quartz (Milky Quartz)

Quartz (Silicon Dioxide - SiO2)

Specular Hematite

Iron Oxide (Fe2O3)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone (likely Siltstone or fine-grained Sandstone)

Sedimentary Rock (Clastic)

Septarian Nodule

Septarian Concretion (CaCO3 with Siderite/Limonite streaks)

Ironstone Concretion (Moqui Marble type)

Iron oxide concretion (Goethite/Hematite and Sandstone)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Prasiolite and Quartz Crystal Cluster

Quartz (SiO2); Prasiolite is a variety of Quartz

Sandstone

Arenite (primarily SiO2)

Agate

Silicon dioxide (SiO2) - Microcrystalline Quartz

Pyrite

Pyrite (FeS2)

Shale

Argillaceous sedimentary rock

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Basalt with Quartz/Calcite Veining

Basalt (principally Plagioclase and Pyroxene)

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Rhodonite

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

Quartz / Chert

Silicon Dioxide (SiO2)

Sandstone

Arenite

Zoisite with Ruby

Anyolite (Ca2Al3(SiO4)3(OH) with Al2O3:Cr)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)