Sedimentary Or Igneous Fragment

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)

Druzy Quartz (part of a Geode)

Silicon Dioxide (SiO2)

Small weathered mineral/rock fragment

Indeterminate; possibly quartz-bearing feldspathic rock or calcite-rich specimen

Small rounded pebble, likely quartz-rich sandstone or granitoid fragment

Uncertain; probable quartz/feldspar-bearing lithic pebble

Pale green rough mineral fragment, possibly green calcite

Calcite (CaCO₃), tentative identification

Chalcedony (Agate/Quartz)

Silicon Dioxide (SiO2)

Mica-rich rock, likely mica schist

Mica schist, composed chiefly of muscovite and/or biotite with quartz and feldspar

Mica schist (likely biotite–muscovite schist)

Mica schist; chiefly quartz and mica minerals (muscovite KAl₂(AlSi₃O₁₀)(OH)₂ and/or biotite)

Weathered foliated metamorphic rock, likely schist or gneiss

Micaceous schist/gneiss; composition likely quartz, feldspar, mica, and altered mafic minerals

Small gray rock fragment, likely granite or diorite

Uncertain; probable coarse-grained silicate rock dominated by feldspar and quartz, possibly biotite/hornblende

Likely mica schist

Mica-rich schist, likely muscovite/biotite with quartz and possibly feldspar

Quartz Geode

Silicon Dioxide (SiO2)

Quartz fragment

Quartz (silicon dioxide, SiO₂)

Unopened Geode

Geode (containing various mineralization like Quartz SiO2)

Weathered schist or gneiss fragment

Quartz–feldspar–mica metamorphic rock; likely mica schist or gneiss

Weathered quartz-bearing rock, possibly calcite vein fragment

Indeterminate; likely quartz (SiO₂) with carbonate minerals such as calcite (CaCO₃)

Weathered quartz-bearing metamorphic rock, likely mica schist or gneiss

Quartz–feldspar–mica assemblage; exact mineral identification requires testing

Quartz

Silicon Dioxide (SiO2)

Weathered metamorphic rock, likely schist or gneiss

Quartz–feldspar–mica metamorphic rock; exact identification requires testing

Quartz

Silicon Dioxide (SiO2)

Likely mica-rich schist fragment

Mica schist; exact mineral identification is uncertain from the image

Quartz-bearing granite or pegmatite fragment

Likely granitic material composed mainly of quartz (SiO₂), feldspar, and possibly biotite or hornblende

Granitic Gravel and Soil

Regolith / Alluvial sediment

Geode

Quartz / Chalcedony nodule

Likely mica-rich schist (possibly phyllite)

Muscovite–biotite schist; exact identification requires examination of a fresh surface

Quartz fragment (Pebble)

Silicon Dioxide (SiO2)

Likely weathered quartz-rich rock fragment

Uncertain; possibly quartz-bearing granitic or metamorphic material (SiO₂-dominant)

Biotite–muscovite schist (mica schist)

Mica schist, likely quartz–feldspar–biotite ± muscovite; exact minerals cannot be confirmed from the photo

Likely biotite-bearing schist

Mica schist, probably biotite-rich; exact identification is uncertain from the photo

Small iron-stained quartz-rich rock fragment

Likely quartz (SiO₂) with iron-oxide staining; exact identification is uncertain from the image

Likely quartz pebble

Quartz (SiO₂), possibly milky or iron-stained quartz

Mica-rich schist

Mica schist, likely muscovite–biotite schist with quartz

Quartz, likely milky or smoky quartz

Quartz (silicon dioxide, SiO₂)

Basalt with Red Sandstone

Mafic extrusive igneous rock with quartzose sedimentary matrix

Gneiss

Metamorphic Gneiss (High-grade regional metamorphism)

Weathered quartz-rich metamorphic rock, likely gneiss or quartzite

Quartz–feldspar–mica metamorphic rock; exact identification is uncertain from the photograph

Likely biotite-rich schist

Mica schist, likely containing biotite and quartz; exact identification requires examination

Coarse Sand or Fine Gravel

Detrital Sedimentary Fragments (mostly SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Granite fragment

Granite; chiefly quartz, alkali feldspar, and plagioclase, with minor mica or amphibole