Mineral, Part Of A Rock

Sandstone

Arenite

Druzy Quartz on Limestone

Silicon Dioxide (SiO2) on Calcium Carbonate (CaCO3)

Sandstone (with potentially high Feldspar/Arkose content)

Clastic sedimentary rock (SiO2 dominated)

Greenstone (likely altered mafic rock)

Chlorite- and amphibole-bearing metabasalt; exact identification requires testing

Basalt with Quartz Vein

Extrusive Igneous Rock / Volcanic Rock

River Rock

Sedimentary clast

Geode (Quartz / Chalcedony Geode)

SiO2 (Silicon Dioxide)

Mixed rock and mineral collection

Unidentified assortment of geological specimens; individual species cannot be determined from the image

Likely tumbled greenstone (identity uncertain)

Greenstone: metamorphosed mafic volcanic rock, commonly composed of chlorite, actinolite, and epidote

Vesicular Basalt

Vesicular Basalt

Druzy quartz on matrix

Quartz (SiO₂), likely microcrystalline-to-fine crystalline drusy quartz

Crushed Granite and Basalt

Phaneritic Igneous Rock / Aphanitic Igneous Rock

Druzy Quartz on Matrix

Silicon Dioxide (SiO2)

Note on Image Identification: Textile

N/A (Anthropogenic material)

Quartz with Sericite and Cinnabar

Silicon Dioxide (SiO2) with muscovite/sericite and mercury sulfide (HgS)

Quartz-rich geode or mineralized cavity in host rock

Likely a quartz-bearing geode; the pale crystals may be quartz (SiO₂), but the photo is not detailed enough for a firm identification.

Geode

Quartz nodule / Chalcedony-lined cavity

Pink quartz bead strand (likely rose quartz or pink dyed quartz)

Quartz, silicon dioxide (SiO₂); probable rose quartz variety, possibly dyed or treated quartz/chalcedony

River Rock / Stream Pebble

Fluvial Clast / Rounded Sedimentary Particle

Unidentified gray mineral/rock fragment

Indeterminate from the photograph; possibly a quartz- or feldspar-bearing rock fragment

Greenstone (likely chlorite- or epidote-rich metamorphic rock)

Greenstone; commonly metamorphosed basalt or dolerite, with chlorite, epidote, and actinolite

Weathered granite

Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, feldspars, and mica

Sandstone with Iron Banding

Arenite with Hematite or Limonite staining (SiO2 with Fe2O3)

Likely serpentinite (green serpentine rock)

Serpentinite, composed chiefly of serpentine-group minerals (antigorite, lizardite, and/or chrysotile)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Vein in Sedimentary Matrix

Silicon Dioxide (SiO2) with host rock

Polished dark-speckled igneous pebble, likely diorite or gabbro

Probable diorite (plagioclase feldspar and hornblende/biotite); exact identification is uncertain from the image

Likely weathered granite or granitic gneiss

Granite: quartz + feldspar + mica; possibly gneiss if the faint texture reflects foliation

Agate Geode

Silicon Dioxide (SiO2) - Chalcedony variety

Quartz vein in host rock

Milky quartz (SiO₂) with likely metamorphic country rock, possibly gneiss or schist

Desert Rose (Baryte or Selenite variant)

Barium Sulfate (BaSO4) or Gypsum (CaSO4·2H2O) with Sand inclusions

Small tan mineral or rock fragment (unidentified)

Indeterminate from the image; no diagnostic features are visible

Quartz (Druzy) in host rock

SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)

Yellow Agate (Banded Chalcedony)

Silicon Dioxide (SiO2)

Weathered iron-rich rock, possibly limonite-bearing basalt or laterite

Indeterminate; likely Fe-oxide/hydroxide–altered mafic rock, dominated by limonite/goethite with silicate minerals

Polished white agate or chalcedony bead

Microcrystalline quartz (SiO₂), likely chalcedony/agate with iron-oxide staining or a brown mineral inclusion

Green serpentine-rich rock (possibly serpentinite)

Serpentinite, composed chiefly of serpentine-group minerals (e.g., lizardite, antigorite, or chrysotile)

Quartz-rich rock, likely granite or quartz-bearing metamorphic rock

Undetermined; possibly granitic rock composed mainly of quartz and feldspar, with mica or other dark minerals

Weathered volcanic rock, likely andesite or basaltic-andesite

Fine-grained plagioclase–pyroxene volcanic rock; possible altered andesite (exact identification requires testing)

Blue Tiger's Eye

Crocidolite (fibrous riebeckite) silicified to Quartz (SiO2)

Sandstone with Manganese Dendrites

Clastic Sedimentary Rock (SiO2 based with MnO2 inclusions)

Vuggy Quartz on Matrix

Crystalline Silicon Dioxide (SiO2)