Multiple

Mixed stream gravel and common rock specimens

Predominantly quartz-rich granitoid, quartzite, sandstone, shale/slate, and mafic volcanic fragments; exact species cannot be determined confidently from the image

Tumbled carnelian agate (likely quartz-rich chalcedony)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide coloration

Red Jasper

Microcrystalline Quartz (SiO2) with Hematite impurities

Quartzite Cobble

Quartzite (SiO2)

Quartzite (River Cobble)

Quartzite (SiO2)

Lapis Lazuli

Lapis Lazuli (Mineral composition: Lazurite, Calcite, Sodalite, and Pyrite)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Quartzite (with Quartz Veining)

Quartzite (SiO2)

Sand Grain (Quartz)

Silicon Dioxide (SiO2)

Botryoidal Chalcedony / Quartz

Silicon Dioxide (SiO2)

Chert with Calcite Veins

Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) intrusions

Lapis Lazuli

Lapis Lazuli (Complex silicate rock containing Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite)

Peridot (Olivine)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Agate

Chalcedony (cryptocrystalline variety of Quartz, SiO2)

Agate Geode / Nodular Chalcedony

Silicon Dioxide (SiO2) with impurities

Likely pink feldspar-rich granite or pegmatite fragment

Uncertain from the image; possibly potassium feldspar (orthoclase/microcline) with quartz

Banded stromatolite (probable fossil limestone)

Microbial carbonate; commonly composed chiefly of calcite (CaCO₃), often classified as stromatolitic limestone

Peridot

Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)

Fossilized Brachiopod

Brachiopoda (Phylum), likely Order Spiriferida or Rhynchonellida

Quartzite River Cobble

Quartzite (primarily SiO2)

Conglomerate (pebble-to-cobble gravel)

Polymictic conglomerate; clast-supported conglomerate in a sandy or silty matrix

Riverstone (Quartzite Pebble)

Quartzite (primarily SiO2)

Lapis Lazuli (polished cabochon)

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

Lapis Lazuli

Sodium aluminum silicate with sulfur (main component: Lazurite [(Na,Ca)8(AlSiO4)6(SO4,S,Cl)2])

Lapis Lazuli

Na8[Al6Si6O24]n(S,Cl,SO4,OH)2

Unakite

Altered Granite (Epidotized Granite)

Sphalerite with Galena

Zinc Sulfide ((Zn,Fe)S) and Lead Sulfide (PbS)

Orthoceras fossil

Orthoceras regulare (Cephalopoda, Orthocerida)

Botryoidal Chalcedony Geode

Silicon Dioxide (SiO2) - Chalcedony / Cryptocrystalline Quartz

Quartz Vein / Milky Quartz

Silicon Dioxide (SiO2)

Mixed mineral and rock specimens

Undetermined assortment; individual pieces may include quartz, feldspar, mica, and other common minerals

Breccia

Polymictic volcanic breccia (likely basaltic-andesitic matrix)

Faceted gemstones, likely mixed small sapphires or spinel

Corundum (Al₂O₃) or spinel (MgAl₂O₄); exact identification requires testing

Fancy Jasper

Chalcedony (SiO2)

Gneiss

Felsic banded gneiss, chiefly quartz–feldspar–mica

Quartz Vein in Host Rock (likely Sandstone or Mudstone)

Silicon Dioxide (SiO2) within Sedimentary Matrix

Botryoidal Chalcedony (Agate/Chert Nodule)

Chalcedony (SiO2)

Botryoidal Chalcedony in Geode/Vug

Silicon Dioxide (SiO2)

Lunar Feldspathic Breccia

Lunar Meteorite (Feldspathic Regolith Breccia)

Banded gneiss

Gneiss, likely quartz–feldspar–mica gneiss

Foliated gneiss, possibly migmatitic gneiss

Gneiss; primarily quartz, feldspar, and mica (biotite/muscovite), with possible amphibole

Quartz Vein in Rhyolite

Silicon Dioxide (SiO2) in extrusive igneous rock