Metamorphic Rock (Composed Of Multiple Minerals)

Greenschist

Greenschist

Quartz Vein in Host Rock

Hydrothermal Quartz (SiO2) in Slates/Schists

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Chalcedony Geode

Chalcedony (SiO2) within a geode structure

River Stone (Granitic Gneiss)

Foliated Granitic Gneiss

Blue Quartz

Quartz (SiO2) with inclusions

Red Sandstone

Arenite (with Iron Oxide / Hematite cementation)

Fuchsite

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Hypersthene (or Enstatite/Ferrosilite)

Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)

Mixed Tumbled Gemstones and River Rocks

Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)

Basalt

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

Granite (Background) and Quartzite/River Pebble (Foreground Heart)

Phaneritic Felsic Igneous Rock (Granite background)

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)

Black Tourmaline

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

Muscovite Mica

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

Granodiorite

Granodiorite (Intermediate intrusive igneous rock)

Blue Tiger's Eye

Crocidolite in Quartz (altered)

Tiger's Eye

Silicon dioxide (SiO2) with fibrous inclusions of crocidolite

Quartzite with inclusions

Metamorphic Rock (Mainly SiO2)

Limestone

CaCO3 (principally composed of Calcite)

Granite

Granite (Felsic Intrusive)

Porphyry (specifically Porphyritic Rhyolite or Andesite)

Porphyritic Igneous Rock (composed of Phenocrysts in an Aphanitic groundmass)

Granite

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

Granitic Pegmatite

Pegmatite (composed primarily of Quartz, Feldspar, and Muscovite mica)

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Emerald in Matrix (Quartz/Schist)

Beryl (Be₃Al₂Si₆O₁₈) with Chromium/Vanadium impurities

Sandstone with Ironstone Banding

Clastic Sandstone (composed of Quartz with Hematite/Limonite bonding)

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.

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Quartz

Silicon Dioxide (SiO2)

Quartz with Iron Stains

Quartz (SiO2) with iron oxide/hydroxide staining

Basalt

Basalt (Mafic volcanic rock)

Granite

Granite (Phaneritic intrusive igneous rock; primarily SiO2 and Al2O3)

Milky Quartz with Country Rock contact

Silicon Dioxide (SiO2) in contact with Metamorphic/Igneous rock

Lapis Lazuli

A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).

Biotite (Black Mica)

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

Quartz (Rock Crystal) with minor impurities

Quartz (SiO2)

Yellow Quartzite (River Stone)

Quartzite (composed primarily of Quartz: SiO2)

Quartzite

Quartzite (composed primarily of Quartz, SiO2)

Quartzite (Yellow/Orange variety)

Quartzite (composed primarily of Silica, SiO2)

Quartzite (Gold/Tan River Cobble)

Quartzite (composed primarily of crystalline SiO2)

Granite

Granite (Phaneritic Quartz-Feldspar Plutonic Rock)