Igneous Or Mineral

Basalt (Weathered Pebble)

Extrusive mafic igneous rock; minerals primarily Plagioclase feldspar and Pyroxene

Peridot

Olivine (Magnesium Iron Silicate), (Mg, Fe)2SiO4

Quartz Geode (with possible Manganese or Goethite coating)

Silicon Dioxide (SiO2)

Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Pyrite-bearing quartz vein rock

Pyrite (FeS₂) with quartz (SiO₂), likely in a schistose or altered host rock

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in Geode form

Man-made Green Quartz (Lab-grown or Treated)

Silicon Dioxide (SiO2) with artificial coloration

Basalt and Quartz pebbles

Basalt (extrusive igneous rock) and Quartz (SiO2)

Tumbled Black Stone

Unknown, possibly Obsidian, Onyx, or Tourmaline

Obsidian and Phantom Quartz

Volcanic Glass (SiO2 + MgO + Fe3O4) and Crystalline Quartz (SiO2)

Black Obsidian and Hematite

Volcanic Glass (SiO2) and Hematite (Fe2O3)

Quartz with Mica/Chlorite inclusions

Silicon Dioxide (SiO2) with phyllosilicate inclusions

Jasper (specifically Polychrome or Desert Jasper)

Silicon Dioxide (SiO2) with impurities

Quartz Vein in Gneiss or Basalt

Milky Quartz (SiO2) within Metamorphic Host Rock

Agate

Silicon dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz crystal, likely iron-stained quartz

Quartz (SiO₂)

White quartz pebble

Quartz (silicon dioxide, SiO₂), likely milky quartz

Fossil shell or shell fragment

Likely a calcareous bivalve or gastropod fragment; precise identification requires locality and microscopy

Milky quartz

Quartz, silicon dioxide (SiO₂)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Milky quartz fragment

Quartz (silicon dioxide, SiO₂)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Garnet Amphibolite (or Garnet Gneiss)

Garnet amphibolite / Garnet-bearing metamorphic rock

Milky quartz with iron-oxide staining and matrix

Quartz, silicon dioxide (SiO₂), likely massive quartz

Likely milky quartz

Quartz (silicon dioxide, SiO₂)

Tumbled milky quartz pebble

Quartz (SiO₂), likely massive milky quartz

Rounded gray pebble, likely quartz-rich granite or gneiss

Indeterminate granitoid; commonly quartz + feldspar + mica

Milky quartz–rich rock

Quartz (SiO₂), likely massive milky quartz with minor dark inclusions

Milky quartz (quartz crystal fragment)

Quartz, silicon dioxide (SiO₂)

Clear Quartz (Druzy)

Crystalline Silicon Dioxide (SiO2)

Banded gneiss

Gneiss, likely biotite–quartz–feldspar gneiss

Banded gneiss pebble

Gneiss, likely quartz–feldspar–mica gneiss

Unidentified transparent crystal or mineral fragment

Cannot be determined from the image; possible quartz, but not diagnostic

Milky quartz

Quartz (silicon dioxide, SiO₂)

Milky quartz with iron-oxide staining

Quartz, silicon dioxide (SiO₂), with limonite/goethite staining

Gneiss (probable)

Quartz–feldspar–mica gneiss; exact mineral composition cannot be confirmed from the image

Polished blue-gray stone, likely labradorite or gneiss

Labradorite-bearing gneiss; plagioclase feldspar-rich rock

Raw quartz (milky quartz)

Quartz, silicon dioxide (SiO₂)

Gneiss (rounded cobble)

Quartz–feldspar–mica gneiss; exact mineral proportions cannot be determined from the image