Igneous Or Mineral

Quartz (Granular)

Silicon Dioxide (SiO2)

Blue Apatite

Apatite Group (Ca5(PO4)3(F,Cl,OH))

Diorite (River Pebble)

Intermediate Phaneritic Igneous Rock

Likely weathered granite or granitic gneiss

Quartz–feldspar–mica rock; possibly gneissic granite

Orthoclase Feldspar

Potassium aluminum silicate (KAlSi3O8)

Milky Quartz with Matrix

Silicon Dioxide (SiO2)

Milky quartz

Quartz (SiO₂), likely massive milky quartz with minor iron-oxide staining and inclusions

Likely clear quartz pebble or glassy quartz fragment

Quartz (silicon dioxide, SiO₂)

Sodalite

Na8(Al6Si6O24)Cl2

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Quartz (Milky or Cloudy)

Silicon Dioxide (SiO2)

Amethyst (Purple), Sulfur (Yellow), and Blue Apatite

SiO2 (Quartz), S (Native Sulfur), Ca5(PO4)3(F,Cl,OH) (Apatite Group)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz (Iron-Stained)

Silicon Dioxide (SiO2)

Rainbow Fluorite

Fluorite (Calcium Fluoride, CaF2)

Calcite on Matrix

Calcium Carbonate (CaCO3)

Pyrite

Iron Sulfide (FeS2)

Mica

Muscovite / Biotite (Phyllosilicate group)

Gneiss

Gneiss (foliated metamorphic rock)

Granite

Granite (Felsic Plutonic Rock)

Likely weathered quartz-bearing rock fragment

Indeterminate; appears to contain quartz (SiO₂) with iron-oxide staining, possibly from quartzite, granite, or pegmatite

Weathered vesicular volcanic rock (likely basalt or andesite)

Amygdaloidal basalt/andesite; cavities may contain calcite, zeolites, or silica minerals

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Extrusive volcanic rock)

Granite Gravel (Pebble)

Intrusive Felsic Igneous Rock

Granite

Phaneritic intrusive igneous rock

Granite

Felsic intrusive igneous rock

Granite

Felsic intrusive igneous rock

Granite

Felsic intrusive igneous rock

Mica

Phlogopite or Biotite group (KMg3(AlSi3O10)(F,OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)

Feldspar-rich igneous rock, likely granite or gneiss fragment

Granite-like quartz–feldspar rock; exact identification is uncertain from the blurred image

Iron-stained quartz rock

Quartz (SiO₂), likely ferruginous quartz or quartz-rich breccia

Epidote with Quartz Vein

Epidote-bearing metamorphic rock with quartz (Ca2(Al,Fe)3(SiO4)3(OH))

Yellow Quartz

Silicon Dioxide (SiO2)

White Quartz

Silicon Dioxide (SiO2)

Sodalite

Na4Al3(SiO4)3Cl (Sodium Aluminum Silicate Chloride)

Quartz Crystal

Silicon Dioxide (SiO2)

Gneiss

Gneiss (Metamorphic rock)

Tumbled blue-gray mineral specimen, likely labradorite

Labradorite, a calcium-rich plagioclase feldspar; approximate formula (Ca,Na)(Al,Si)₄O₈

Massive Quartz with Host Rock

Silicon Dioxide (SiO2)