Identify any rockfrom a photo.

Quartz-rich sandstone

Sandstone, chiefly quartz (SiO₂) with likely feldspar and iron-oxide cement

Galena

Galena (lead sulfide, PbS)

Quartz-rich rock fragment, possibly milky quartz

Quartz (SiO₂), likely a small vein-quartz or quartz-bearing rock fragment

Likely obsidian (rough fragment)

Volcanic glass, predominantly silica-rich rhyolitic composition (SiO₂-rich, noncrystalline)

Blue-green fluorite or copper-bearing mineral specimen

Fluorite (CaF₂), tentatively; blue-green coloration may indicate trace copper or other impurities

Red jasper (likely iron-rich chert)

Microcrystalline quartz (SiO₂) colored by hematite/goethite

Clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Quartz (likely milky quartz or quartz glass-like fragment)

Quartz, silicon dioxide (SiO₂)

Mounted faceted gemstone ring

Likely diamond (carbon, C), though the image is insufficient for definitive identification

Faceted pale pink gemstone ring, likely morganite or rose quartz

Morganite: pink beryl, Be₃Al₂Si₆O₁₈; alternatively quartz, SiO₂

Black onyx or black obsidian bead bracelet

Likely chalcedony (microcrystalline quartz, SiO₂) if onyx; alternatively volcanic glass (obsidian)

Milky quartz (probable)

Quartz, silicon dioxide (SiO₂)