Igneous And Metamorphic

Milky quartz

Quartz (silicon dioxide, SiO₂)

Milky Quartz

Silicon Dioxide (SiO2)

Hypersthene (or Enstatite/Ferrosilite)

Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Fossil-bearing fine-grained sedimentary rock

Likely fossiliferous mudstone or shale; visible feature may be a plant fragment, trace fossil, or mineral vein

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Milky quartz with iron staining

Quartz (SiO₂), likely massive vein quartz

Milky quartz

Quartz (SiO₂)

Quartz vein rock (likely iron-stained milky quartz in host rock)

Predominantly quartz (SiO₂), with rusty iron-oxide staining and possible feldspar/host-rock fragments

Mica

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

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Pegmatite

Pegmatitic Granite containing Quartz, Feldspar, and Schorl

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Small dark mineral or rock fragment

Undetermined; possibly a dark mafic mineral such as biotite or magnetite

Likely polished/tumbled dark mineral or glassy rock fragment

Indeterminate from image; possibly hornblende, schorl tourmaline, or obsidian

Pyrite

Iron Sulfide (FeS2)

Likely quartz-bearing rock or mineral fragment

Indeterminate; possibly quartz (SiO₂) with iron-oxide staining and darker matrix

Milky Quartz

Crystalline Quartz (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Likely magnetite-rich rock fragment

Magnetite (Fe₃O₄), possibly in a fine-grained host rock

Likely magnetite-bearing rock

Magnetite (Fe₃O₄), possibly in a mafic host rock

Milky quartz

Quartz (silicon dioxide, SiO₂)

Milky Quartz

Silicon Dioxide (SiO2)

Rough Citrine Quartz

Citrine (Silicon Dioxide, SiO2 with iron impurities)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Iron-stained quartz crystal cluster

Quartz (SiO₂), likely iron-oxide-stained; exact variety uncertain

Milky quartz with a dark mineral inclusion

Quartz (SiO₂), likely containing a small inclusion of biotite or another dark mineral

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Milky and Ferruginous Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)