Metamorphic And Igneous

Milky quartz (iron-stained quartz)

Quartz, silicon dioxide (SiO₂)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Red Quartz

Silicon Dioxide (SiO2) with Hematite inclusions

White quartz-rich pebble

Likely quartzite or milky-quartz pebble (SiO₂)

Milky quartz

Quartz (SiO₂), likely massive milky quartz with minor iron-oxide staining and inclusions

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Emerald

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Quartz crystal with Pyrite inclusions

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Calcite

Calcite (CaCO3)

Quartz vein rock

Milky quartz with smoky quartz; chiefly silicon dioxide (SiO₂)

Quartz Pebble

Silicon Dioxide (SiO2)

Gold-bearing quartz vein rock

Milky quartz (SiO₂) with probable native gold and iron-oxide staining

Blue cabochon gemstone ring

Uncertain; likely blue sapphire (corundum, Al₂O₃), blue topaz, or synthetic glass/spinel

Polished green-inclusion stone, likely chlorite-included quartz

Quartz (SiO₂) with chlorite inclusions; exact identification is uncertain from the photograph

Milky quartz vein rock

Quartz (SiO₂), likely in a quartz-rich host rock with minor iron-stained minerals

Bull Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Polished blue-gray mineral specimen, likely galena-bearing ore

Galena (PbS), possibly mixed with quartz/calcite and secondary copper minerals

Milky quartz vein fragment

Quartz, silicon dioxide (SiO₂)

Faceted yellow gemstone, likely citrine

Citrine (quartz), SiO₂; possibly yellow sapphire or synthetic glass without testing

Massive Quartz with Host Rock

Silicon Dioxide (SiO2)

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

Ruby

Corundum (Al2O3:Cr)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Metasedimentary or Igneous Matrix

Red faceted gemstone ring

Likely synthetic ruby or red spinel; exact identification requires testing

Blue Sapphire and Diamond (Set in Metal)

Corundum (Al2O3) and Diamond (C)

Rose Quartz

Rose Quartz (SiO2)

Green Calcite

Calcite (CaCO3)

Granite Gneiss or Granitoid River Rock

Granitoid / Gneiss

Quartz River Pebble with Algae

Silicon Dioxide (SiO2) with organic biofilm

Quartzite (river pebble) and Gabbro (crushed rock)

Quartzite (metamorphosed Quartz Sandstone, SiO2) and Gabbro (Plagioclase-Clinopyroxene rock)

Quartzite or Quartz pebble

SiO2 (Silicon dioxide) with impurities

Riverstone (Quartzite/Granite Cobble)

Silicon Dioxide (SiO2) based Quartzite or Silicate-rich Granite

Sapphire (Corundum variety)

Sapphire (Al₂O₃)

Gold (Processed)

Gold (Au)

Calcite

Calcite (CaCO3)

Rutilated Quartz

SiO2 with TiO2 inclusions (Rutile)

Greenish rock with white veins, possibly epidote or chlorite bearing rock with quartz/calcite veins

Altered mafic rock or Epidosite

Mixed beach pebbles; likely quartzite, granite, and iron-stained metamorphic rock

Predominantly quartzite (SiO₂), granite (quartz–feldspar–mica), and weathered iron-rich rock

Fulonite (Fulgurite-like)

Fulgurite (SiO2 fused silica/lechatelierite)

Quartz (Druzy) in host rock

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

Quartz Vein in Host Rock (often Granite or Schist)

Silicon Dioxide (SiO2) within host matrix