Sedimentary Or Igneous (Host Environment)

Chert (Flint nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Quartz (likely Jasper or Chert variety)

Quartz (SiO₂)

Quartz-rich granite or granitic gneiss cobble

Granite; primarily quartz, feldspar, and mica, possibly with gneissic deformation

Quartz-bearing pegmatitic rock, likely quartz–feldspar–mica specimen

Granitic pegmatite; primarily quartz (SiO₂), feldspar, and mica, with possible iron-oxide staining

Pyrite

Iron Sulfide (FeS2)

Milky quartz–rich rock

Quartz (SiO₂), likely massive milky quartz with minor dark inclusions

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Quartz Vein in Siltstone

Siltstone with Quartz (SiO2) inclusion

Limestone (Grey and White specimens)

Calcium Carbonate (CaCO3)

Weathered porphyritic volcanic rock

Likely altered andesite or rhyolite porphyry

Iron-stained Quartz

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Biotite-bearing gneiss or schist

Quartz–feldspar–mica metamorphic rock, likely mica schist/gneiss

Pyrite-bearing rock (likely pyrite-rich ore)

Pyrite, FeS₂, in a fine-grained host rock

Chert (White Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pegmatite with Quartz and Feldspar

Intrusive Igneous Rock

Weathered quartz-bearing metamorphic rock

Likely quartz–feldspar schist or gneiss, possibly with iron-oxide alteration

Quartz-veined basalt or mafic schist

Basaltic rock dominated by plagioclase–pyroxene minerals, with milky quartz/calcite veins

Milky quartz vein in altered host rock

Quartz (SiO₂), likely with feldspar, mica, and iron-oxide alteration

Milky quartz vein rock

Quartz, silicon dioxide (SiO₂), likely massive vein quartz with iron-oxide staining

Druzy Quartz on Ironstone

Silicon Dioxide (SiO2) on Limonitic Ironstone

Chert / Flint Nodules in Sandstone

Microcrystalline Quartz (SiO2) within Clastic Sedimentary Rock

Chert (Chalcedony/Agate variety)

Silicon dioxide (SiO2)

Vuggy Quartz on Matrix

Crystalline Silicon Dioxide (SiO2)

Polished reddish-brown gemstone, likely carnelian

Carnelian: chalcedony, microcrystalline quartz (SiO₂), colored mainly by iron oxides

Iron-stained Quartz (with Limonite/Hematite)

Silicon Dioxide (SiO2) with Iron Oxide inclusions (FeO(OH) or Fe2O3)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Smoky Quartz and Chalcedony Geode Fragment

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 inclusions)

Limestone

Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)

Small polished dark-blue stone, likely sodalite or blue aventurine

Probable sodalite (Na8(Al6Si6O24)Cl2); identification is uncertain from the image

Ruby (Pink to Red Corundum)

Al2O3 (Corundum with Chromium impurities)

Quartz (Citrine or Iron-Stained variety)

Silicon Dioxide (SiO2)

Pegmatitic pink feldspar–quartz rock

Granitic pegmatite; chiefly microcline/orthoclase feldspar (KAlSi₃O₈), quartz (SiO₂), and minor mica

Uncertain small stone; possibly weathered quartz-bearing rock

Indeterminate from image; candidate materials include quartz-rich pebble or altered silicate rock

Iron-stained quartz vein in host rock

Quartz (SiO₂), with iron-oxide staining; host rock is uncertain from the image

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2) within Sedimentary host rock

Weathered copper-bearing rock (likely malachite-stained basalt or greenstone)

Malachite, Cu₂CO₃(OH)₂, as a secondary coating on a mafic host rock; exact identification requires testing

Bull Quartz with Mica and Host Rock

Massive Quartz (SiO2) with Muscovite/Chlorite inclusions

Chalcedony (Botryoidal Agate vein)

Chalcedony (Microcrystalline Quartz) - SiO2

Likely magnetite-bearing rock

Magnetite (Fe₃O₄), possibly in a mafic host rock