Metamorphic Rock (Primarily Composed Of Minerals)

Basalt

Mafic Volcanic Rock (composed of plagioclase, pyroxene, and olivine)

Quartzite

Quartzite (primarily SiO2)

Quartz-veined Schist (or Metasandstone)

Metamorphic Rock with Quartz Veining (SiO2)

Granite

Phaneritic Felsic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)

Granite

Plutonic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Granite

Phaneritic Felsic Igneous Rock (composed primarily of Quartz and Alkali Feldspar)

Vesicular Basalt

Mafic Volcanic Rock (Basalt)

Turquoise

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

Schist

Mica Schist

Quartz Vein in Host Rock (Pebble)

Quartz (SiO2) with sandstone or siltstone matrix

Amber

(C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.

Sandstone (Pebble/Cobble)

Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)

Banded Iron Formation (BIF)

Banded Iron Formation (composed primarily of Hematite [Fe2O3], Magnetite [Fe3O4], and Chert [SiO2])

Jadeite Jade

NaAlSi2O6 (Sodium Aluminum Silicate)

Black Tourmaline

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Diorite (with Salt-and-Pepper Texture)

Diorite (Intrusive Igneous Rock)

Basalt with Olivine Phenocrysts

Porphyritic Basalt (containing Mg2SiO4 - Fe2SiO4)

Muscovite Mica

Muscovite (Potassium Aluminum Silicate Hydroxide Fluoride), KAl2(AlSi3O10)(OH,F)2

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)

Granodiorite

Granodiorite (Intermediate intrusive igneous rock)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Fossilized Coral

Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)

Fossil Coral

Coral Limestone (a type of biogenic sedimentary rock)

Moonstone

Orthoclase feldspar ((K,Na)AlSi3O8)

Tiger's Eye

Silicon dioxide (SiO2) with fibrous inclusions of crocidolite

Quartzite

Quartzite (primarily SiO2)

Tumbled Stones (various)

Mixed Silica-based Minerals (primarily Quartz and Chalcedony)

Jadeite (Jade)

Jadeite (NaAlSi2O6)

Sunstone

Oligoclase or Andesine (Plagioclase Feldspar) - (Ca, Na)((Al, Si)2Si2O8)

Granodiorite

Granodiorite (containing Quartz, Plagioclase, Orthoclase, Biotite/Hornblende)

Blue Sapphire

Corundum (Al2O3)

Quartzite Pebble

Quartzite (primarily SiO2)

Zebra Marble

Metamorphosed Alabaster/Limestone (CaCO3)

Emerald in Matrix (Quartz/Schist)

Beryl (Be₃Al₂Si₆O₁₈) with Chromium/Vanadium impurities

Picture Jasper

Silicified sedimentary or volcanic rock (primarily SiO2)

Unakite

Epidotized Granite

Sandstone (likely Arkosic or Lithic)

Clastic Sedimentary Rock (SiO2 with accessory minerals)

Amygdaloidal Basalt

Amygdaloidal Basalt containing Zeolite or Quartz (SiO2/Silicates)

Concretion or Geode (unbroken)

Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.

Pyrite

Iron Disulfide (FeS2)

Red Sandstone

Arenite (primarily Quartz, SiO2, with Iron Oxide cementing agent)

Chrysocolla and Malachite Beads

Hydrated copper silicates (Chrysocolla) and Copper carbonate hydroxide (Malachite)