Antropogenic (Man Made Glass Byproduct)

Quartz-rich rock, possibly milky quartz or quartzite fragment

Quartz (SiO₂), potentially quartzite if metamorphic

Yellow-brown quartz/chalcedony fragment

Quartz, SiO₂; likely microcrystalline chalcedony with iron-oxide staining

Green cabochon gemstone pendant, likely turquoise or dyed green turquoise

Probably turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; exact identification requires testing

Chert (Gravel Bit)

Microcrystalline silica (SiO2)

Milky quartz with iron-stained matrix

Quartz (silicon dioxide, SiO₂)

Tumbled quartz pebble, likely iron-stained quartz or citrine

Quartz (SiO₂), possibly ferruginous quartz or pale citrine

Grey Granite

Phaneritic Felsic Intrusive Igneous Rock

Smoky quartz (likely)

Quartz, silicon dioxide (SiO₂)

Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')

Silicon Dioxide (SiO2) with artificial pigment

Speckled rounded stone, likely granite or granitic gneiss

Granite/granitic gneiss; primarily quartz (SiO₂), feldspar, and dark mica or amphibole

Carved lavender chalcedony (likely agate) animal figurine

Microcrystalline quartz, SiO₂; probable chalcedony or pale lavender agate

Tumbled dark red-brown stone, possibly jasper

Likely opaque microcrystalline quartz (chalcedony/jasper), SiO₂; exact identification is uncertain from the blurred photograph

Tumbled brown jasper

Jasper, microcrystalline quartz (SiO₂) with iron-oxide inclusions

Quartz Vein in Host Rock

Crystalline Silicon Dioxide (SiO2) in Pelitic or Shaly Matrix

Likely vesicular basalt (scoria)

Basaltic scoria; chiefly plagioclase, pyroxene, and olivine with vesicles

Milky quartz (rough quartz chunk)

Quartz, silicon dioxide (SiO₂)

Polished white quartz-rich pebble

Microcrystalline quartz (SiO₂), likely milky quartz or quartzite

Polished carnelian/chalcedony

Carnelian, a reddish-orange variety of microcrystalline quartz (SiO₂)

Green cabochon gemstone pendant

Indeterminate; likely dyed green turquoise, chrysoprase, or opaque beryl set with blue/clear accent stones

Quartz (possibly milky quartz)

Quartz (Silica; SiO₂)

Stainless Steel Spoon

Iron-Chromium Alloy (Fe + Cr + Ni)

Amethyst

Amethyst (Silicon Dioxide, SiO2 + Fe4+ impurities)

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly quartz (SiO₂) with iron-oxide staining and minor feldspar/mica

Tumbled sodalite with white calcite veining

Sodalite, Na8(Al6Si6O24)Cl2, commonly intergrown with calcite, CaCO3

Banded Gneiss

Gneiss (pronounced 'nice')

Chalcedony (likely agate/chert variety)

Microcrystalline quartz, SiO₂

Iron-stained quartz crystal

Quartz (SiO₂), likely iron-oxide-coated or included

Iron-rich quartzite or weathered ironstone

Quartzite dominated by quartz (SiO₂), with iron oxides/hydroxides such as hematite and goethite

Flesh-colored Quartzite

Quartzite (SiO2)

Tumbled quartz crystal (likely smoky or iron-stained quartz)

Quartz, silicon dioxide (SiO₂)

Chert (variant Flint/Jasper)

Microcrystalline Opaline Silica (SiO2)

Granite fragment

Granite

Quartz (milky quartz), possibly calcite

Quartz: SiO₂; visual identification is uncertain because the specimen is wet and lacks diagnostic crystal faces

Pegmatitic quartz–feldspar rock with dark mica

Granitic pegmatite; quartz (SiO₂), feldspar, and biotite mica

Yellow chalcedony (likely heat-treated or resin-coated)

Microcrystalline quartz, SiO₂

Porphyritic rhyolite (likely lithophysal/vesicular rhyolite)

Rhyolite; chiefly quartz and alkali feldspar, with minor plagioclase and iron-bearing minerals

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly crystalline quartz (SiO₂), possibly with mica and feldspar

Milky quartz cluster

Quartz (silicon dioxide, SiO₂)

Blue-green fluorite crystal

Fluorite (calcium fluoride, CaF₂)

Chert (or Carnelian Agate)

Microcrystalline Quartz (SiO2)

Polished black stone, likely black obsidian

Obsidian — volcanic glass, chiefly SiO₂

Milky quartz-rich rock

Quartz (SiO₂), likely massive milky quartz with minor iron-stained gangue