Sedimentary Or Metamorphic

Seashell (Calcium Carbonate)

Calcium Carbonate (CaCO3)

Magnetic Hematite

Magnetized Hematite (an iron oxide mineral, Fe2O3, that has undergone magnetization)

Almandine Garnet & Tumbled Citrine Quartz

Fe3Al2(SiO4)3 (Garnet) and SiO2 (Quartz)

Green Aventurine (Green Quartzite)

Silicon Dioxide (SiO2) with inclusions of Fuchsite (chromium-rich mica)

Iolite (Cordierite)

Magnesium Iron Aluminum Silicate (Mg,Fe)2Al4Si5O18

Red Garnet

Almandine (Fe3Al2(SiO4)3) or Pyrope (Mg3Al2(SiO4)3)

Anthracite Coal

Anthracite (Carbon-based metamorphic rock, 86-97% C)

Slate

Foliated Metamorphic Rock (composed mainly of Quartz, Illite, and Chlorite)

Wishing Stone with Quartz Veins

Quartzite or Quartz-veined Metamorphic Rock (composed mainly of SiO2)

Greenschist

Chlorite schist (Metamorphic rock dominated by chlorite, epidote, and actinolite)

Quartzite

Quartzite (primarily SiO2)

Quartzite

Quartzite (primarily SiO2)

Quartzite

Quartzite (SiO2)

Tiger's Eye (Rough)

Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)

Quartzite

Quartzite (SiO2)

Ferruginous Sandstone

Arenite with Iron-Oxide cement (Fe2O3 · nH2O)

Brown Sandstone

Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)

Quartz (Druzy) on Matrix

Silicon Dioxide (SiO2)

Bull Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Red Garnet (Pyrope or Almandine)

Magnesium aluminum silicate (Mg3Al2(SiO4)3) or Iron aluminum silicate (Fe3Al2(SiO4)3)

Milky Quartz (with trace inclusions)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Mica-rich Pegmatite

Pegmatite (rich in Muscovite and Biotite)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz with Chlorite/Moss Infusions

Silicon Dioxide (SiO2)

Serpentine Schist with Quartz Vein

Serpentine Schist (a type of Metamorphic rock). The white band is likely Quartz (SiO2).

Lapis Lazuli (polished cabochon)

Lazurite-rich metamorphic rock (approx. Na6Ca2Al6Si6O24(SO4,S,Cl)2)

Slate

Slate (foliated metamorphic rock, primarily composed of quartz, illite, chlorite, and micas)

Greenstone (River Pebble)

Metabasalt / Greenschist

Schist

Mica Schist

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Yellow Aventurine

Quartz variety (SiO2) with inclusions

Gold Ore in Quartz

Native Gold (Au) in Quartz (SiO2) matrix

Epidote with Quartz/Feldspar

Epidote (Ca2(Al, Fe)3(SiO4)3(OH)) with associated minerals in a host rock

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Rough Tanzanite

Zoisite (Ca2Al3(SiO4)3(OH))

Milky Quartz (Common Quartz)

Quartz (Silicon Dioxide, SiO2)

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)

Milk Quartz (Vein Quartz)

Quartz (Silicon Dioxide, SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Corundum (variety Ruby/Sapphire)

Aluminum Oxide (Al2O3)