Rock

Quartz vein in mica-rich host rock

Milky quartz (SiO₂) in a mica-rich metamorphic matrix, likely schist

Shale

Shale (claystone/mudstone)

Serpentinite (often called Jade or Nephrite substitute)

Serpentinite (composed primarily of Antigorite, Lizardite, or Chrysotile)

Red sandstone

Ferruginous quartz arenite (iron-oxide–cemented sandstone)

Granite

Intrusive Igneous Rock

Weathered granite (likely)

Granite, a quartz–feldspar–mica intrusive igneous rock

Weathered granitic or gneissic cobble

Likely altered granite/granodiorite; exact identification requires a fresh surface and testing

Quartz-Veined Gneiss or Metamorphic Rock with Quartz Veins

Quartz-veined metamorphic rock (Silicate mineral assemblage)

Dark-colored Igneous Rock (likely Basalt or Diabase)

Basalt (extrusive igneous) or Diabase (intrusive igneous)

Gneiss

Gneiss (High-grade metamorphic rock)

Mixed Rock Assortment

Polylithic geological specimens

Quartz with Iron Staining

Silicon Dioxide with Iron Oxides (SiO2 + Fe2O3)

Quartz with Chlorite inclusions

SiO2 with (Mg,Fe)3(Si,Al)4O10(OH)2⋅(Mg,Fe)3(OH)6

Green Jasper

Microcrystalline Quartz (SiO2)

Amphibolite

Amphibolite, typically composed mainly of hornblende (amphibole) and plagioclase feldspar

Drusy quartz on a matrix (tentative)

Quartz, SiO₂, as a fine-grained drusy coating; associated matrix is unclear from the image

Likely banded agate pebble

Microcrystalline quartz (SiO₂), typically chalcedony; identification is uncertain from the image

Rounded greenstone pebble

Likely serpentinite or chlorite-rich metamorphic rock; exact identification requires testing

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Quartz (Smoky/Granular variety)

Silicon Dioxide (SiO2)

Gray rock (possibly basalt or fine-grained granite)

Undetermined; no diagnostic minerals are visible

Quartz Vein in Gneiss or Basalt

Milky Quartz (SiO2) within Metamorphic Host Rock

Mixed tumbled river pebbles and beach stones

Polymictic alluvial gravel; components include quartz, chert, jasper, sandstone, and altered volcanic rocks

Mixed rough mineral specimens, likely quartz-bearing rocks

Probable quartz (SiO₂), with possible feldspar, iron oxides, and altered host rock

Red jasper

Jasper, an opaque microcrystalline quartz variety (SiO₂), colored mainly by iron oxides

Shale

Laminated Fissile Pelite

Dalmatian Stone

Peralkaline Quartz-Feldspar Porphyry with Arfvedsonite

Serpentine-rich greenstone

Serpentinite, dominated by serpentine-group minerals (antigorite/lizardite/chrysotile), with possible chlorite, magnetite, and talc

Granite fragment

Granite, chiefly quartz (SiO₂), feldspar, and mica

Rounded gray pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly basalt (plagioclase ± pyroxene/olivine)

Brecciated Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Granodiorite with Quartz Veining

Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins

Basalt

Basalt

Quartz Geode

Silicon Dioxide (SiO2)

Banded Slate or Siltstone with Quartz/Calcite Veins

Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)

Dalmation Jasper (or Dalmation Stone)

Dalmation Stone (composed of Perthite, Quartz, and Arfvedsonite)

Granodiorite

Phaneritic-textured Intrusive Granodiorite

River Pebble (Gravel)

Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)

Diorite

Diorite (Intermediate intrusive igneous rock)

Milky Quartz

Silicon Dioxide (SiO2)

Banded Slate

Slate (Metamorphosed Siltstone/Mudstone)

Moonstone

Orthoclase (Potassium Aluminum Silicate), Formula: (K,Na)AlSi3O8