Sedimentary Or Igneous Fragment

Small quartz-rich stone, possibly iron-stained quartz or jasper

Quartz (SiO₂), potentially with iron-oxide inclusions

Rounded quartz pebble (tentative)

Quartz, silicon dioxide (SiO₂)

Weathered sandstone fragment

Quartz-rich sandstone, likely feldspathic or lithic sandstone

Weathered quartz-rich rock fragment

Indeterminate; possibly weathered granite, quartzite, or rhyolite

Quartz Pebble

Silicon Dioxide (SiO2)

Fossilized marine shell fragment

Likely a bivalve or gastropod shell preserved as calcite (CaCO₃)

Raw quartz fragment

Quartz (SiO₂), likely milky or included quartz

Weathered granite or granitic rock fragment

Granite; quartz–feldspar–mica aggregate

Raw milky quartz (likely quartz/chalcedony fragment)

Quartz, silicon dioxide (SiO₂)

Gneiss

Gneiss

Quartz crystal fragment (likely milky quartz)

Quartz, silicon dioxide (SiO₂), trigonal crystal system

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Milky or Clear fragment)

Silicon Dioxide (SiO2)

Quartz (Milky/Crystalline fragment)

Silicon Dioxide (SiO2)

Quartz Druze on Matrix (Geode Fragment)

Quartz (Silicon Dioxide, SiO2)

Milky Quartz Fragment

Silicon Dioxide (SiO2)

Vesicular basalt (scoriaceous volcanic rock)

Scoria; iron-rich vesicular basalt, primarily plagioclase, pyroxene, olivine, and volcanic glass

Quartz vein in foliated metamorphic rock

Likely quartz-bearing schist or gneiss; visible crystal is quartz (SiO₂)

Shale or slate fragment

Fine-grained phyllosilicate rock, likely slate (metamorphosed shale)

Fossil-bearing fine-grained sedimentary rock

Likely fossiliferous mudstone or shale; visible feature may be a plant fragment, trace fossil, or mineral vein

Biotite-bearing gneiss or schist

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

Weathered, quartz-rich metamorphic rock (likely schist or gneiss)

Quartz–feldspar–mica schist/gneiss, with surface lichens and iron-oxide staining

Clear Quartz

Silicon Dioxide (SiO2)

Gneiss (Gneissic Granite Pebble)

Metamorphic rock rich in Quartz, Feldspar, and Mica

Weathered metamorphic rock, possibly schist or gneiss

Indeterminate; likely quartz–feldspar–mica rock, potentially greenschist or gneiss

Mica-bearing metamorphic rock, likely schist

Muscovite/biotite mica schist with quartz and feldspar

Fossiliferous limestone (reef or shell-rich limestone)

Bioclastic calcarenite/calcirudite; predominantly calcite (CaCO₃)

Orange mineral fragment, possibly citrine or iron-stained quartz

Quartz (SiO₂), tentatively iron-included quartz/citrine

Milky Quartz

Silicon Dioxide (SiO2)

Weathered sandstone or fine-grained graywacke

Clastic sedimentary rock; chiefly quartz (SiO₂), feldspar, and lithic fragments bound by silica, calcite, or iron-oxide cement

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz crystal fragment

Quartz (silicon dioxide, SiO₂)

Small quartz pebble or silica-rich mineral fragment

Quartz (SiO₂), tentative

Tumbled quartz-rich stone, possibly milky quartz or calcite

Quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing

Likely weathered schist or gneiss fragment

Micaceous quartz-feldspar metamorphic rock; exact identification requires testing

Milky quartz

Quartz (silicon dioxide, SiO₂)

Weathered granite or granitic pegmatite fragment

Granite; chiefly quartz, feldspar, and mica (variable composition)

Pyrite-bearing schist or quartzite

Micaceous quartz-rich metamorphic rock with pyrite (FeS₂)

Weathered basalt or iron-rich volcanic rock

Mafic volcanic rock, likely basalt; exact identification requires testing

Quartz-veined metamorphic rock, likely schist or gneiss

Quartz–feldspar–mica rock; exact identification requires testing

Weathered granite or granitic gneiss fragment

Quartz–feldspar–mica granite; possibly foliated granitic gneiss

Quartz-rich rock fragment, possibly milky quartz or quartzite

Quartz (SiO₂), or quartzite if the grains are fused