Mineral, Specifically A Rock Fragment

Mixed rock specimens; likely pink feldspar/quartz and a dark, mica-bearing rock

Tentative visual identification: pink K-feldspar–quartz-rich granite/pegmatite fragments and a dark amphibole- or biotite-rich metamorphic rock; exact identification is uncertain from the image

Quartz Druze on Matrix (Geode Fragment)

Quartz (Silicon Dioxide, SiO2)

Quartz (Microcrystalline/Gravel)

Silicon Dioxide (SiO2)

Quartz-bearing rock fragment

Likely quartz (SiO₂) with iron-oxide staining and possible feldspar/matrix minerals

Chalcedony (Agate/Carnelian)

Cryptocrystalline Silicon Dioxide (SiO2)

Unknown brown-and-gold rock fragment

Undetermined; possibly iron-stained quartz, mica schist, or sulfide-bearing ore

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Granitic Pegmatite

Granite Pegmatite (coarse-grained intrusive igneous rock)

Pink Granite (River Pebble)

Felsic Intrusive Igneous Rock

Pink Granite

Phaneritic plutonic rock (Granite)

Dalmatian Jasper

Dalmatian Stone (Felsite with Arfvedsonite/Tourmaline)

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone

Arenite (Clastic Sedimentary Rock)

Mica Schist

Mica Schist (primarily Muscovite and Quartz)

Likely raw rose quartz or pink feldspar fragment

Quartz (SiO₂), possibly pink feldspar such as orthoclase

Red jasper

Jasper, an opaque microcrystalline quartz variety (SiO₂), colored mainly by iron oxides

Quartz-rich rock fragment (tentative)

Quartz, silicon dioxide (SiO₂), possibly in a weathered host rock

Granite (Pink/Potassium Feldspar Granite)

Felsic Plutonic Rock (Potassium Feldspar, Quartz, Mica, and Amphibole)

Clear Quartz

Silicon Dioxide (SiO2)

Unidentified dark, flat specimen

Indeterminate; image resolution is insufficient for mineral identification

Weathered, iron-stained rock (likely sandstone or breccia)

Indeterminate clastic sedimentary rock; possible ferruginous sandstone or weathered breccia

Quartz Heart or Arrowhead Shape

Silicon Dioxide (SiO2)

Coarse Sand Grain / Lithic Fragment

Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)

Oolitic Chert

Silicon Dioxide (SiO2) with Oolitic texture

Weathered conglomeratic rock, likely iron-stained sandstone

Probable ferruginous, clast-bearing sandstone; exact identification requires examination of a fresh surface

Mixed rough mineral specimens, likely quartz-bearing rocks

Probable quartz (SiO₂), with possible feldspar, iron oxides, and altered host rock

Quartz Druzy (Geode Fragment)

Silicon Dioxide (SiO2)

Weathered brown rock fragment, possibly iron-rich sandstone or altered basalt

Indeterminate; likely an iron-oxide–stained silicate rock

Small metallic-looking mineral/rock fragment

Indeterminate from image; possible pyrite-bearing sulfide rock or native-metal/meteorite fragment

Likely quartz-rich rock or mineral fragment

Quartz (SiO₂), possibly in a pegmatitic or granitic matrix

Sandstone

Sandstone (composed predominantly of SiO2)

Sandstone

Arenite (SiO2 based)

Sandstone Pebble

Arenite (SiO2 based)

River cobble (Greywacke/Sandstone)

Sandstone / Greywacke

Sandstone

Arenite (SiO2 dominant)

Sandstone (likely Conglomerate or Gritstone)

Arenite (SiO2 based)

Sandstone

Clastic sedimentary rock (SiO2 primary)

Sandstone

Arenite (SiO2 principal)

Basalt (Vesicular)

Basalt (Mafic Extrusive Igneous Rock)

Sandstone

Clastic sedimentary rock

Pink feldspar-rich granite

Granite, composed chiefly of quartz, potassium feldspar, and plagioclase, with minor mica or other minerals

Sandstone

Arenite (SiO2 with various cementing minerals)