Milky Quartz
Silicon Dioxide (SiO2)
Category
Browse sedimentary or metamorphic derived specimens identified by the Rock Identifier community.
Milky Quartz
Silicon Dioxide (SiO2)
Pyrite (or Fool's Gold)
Pyrite (FeS₂)
Chalcedony (Banded/Mottled Variety)
Chalcedony (a cryptocrystalline variety of Quartz, SiO2)
Calcite
Calcite (Calcium Carbonate, CaCO3)
Quartz Pebble
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Milky Quartz with Iron Inclusions
Quartz (Silicon Dioxide, SiO2)
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Quartz (likely milky/gray variety)
Quartz (SiO₂)
Micaceous Sandstone or Quartzite
Sandstone (lithified quartz grains, often with mica) or Quartzite (metamorphosed sandstone)
River Pebble (likely Quartzite or Chert)
Silicon Dioxide (SiO2) crystal conglomerate
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Yellow Quartz (Citrine-colored Quartz)
Silicon Dioxide (SiO2)
Smoky Quartz (Vein Quartz)
Quartz (Silicon Dioxide, SiO2)
Quartz (possibly milky quartz or quartz with inclusions)
SiO2 (Silicon Dioxide)
Agate
Agate (a cryptocrystalline variety of Quartz, SiO₂)
Quartz
Quartz (SiO₂)
Glacial Erratic (Sandstone/Quartzite)
Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)
Limonite-stained Quartz / Quartzite
Silicon Dioxide (SiO2) with iron hydroxides (FeO(OH)·nH2O)
Diorite (Gneissic)
Diorite
Quartz
Silicon Dioxide (SiO2)
River Pebble (Likely Quartzite or Chert)
Silicon Dioxide (SiO2)
Weathered Quartzite or Chert Pebble
Silicon Dioxide (SiO2)
River Cobble (likely Quartzite or Limestone)
SiO2 (Quartzite dominant) or CaCO3 (Limestone dominant)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Quartz (specifically Milky/Gray Quartz)
Silicon Dioxide (SiO2)
Tiger's Eye and Carnelian Quartz
Silicon Dioxide (SiO2)
Quartz (Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Fluorite and Rose Quartz
Fluorite (CaF2), Rose Quartz (SiO2)
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Amethyst
Amethyst (Purple Quartz); formula: SiO2 (Silicon Dioxide)
Amethyst
Amethyst (variety of Quartz, SiO2)
Quartz (Granular Milky Quartz fragment)
Silicon Dioxide (SiO2)
Quartz in Matrix (possibly with Biotite or Hornblende)
Quartz (Silicon Dioxide, SiO2) in Granitic Matrix
Banded Agate (Tumbled)
Agate (Silicon Dioxide, SiO2 - Cryptocrystalline Quartz)
River Cobble (likely Sandstone or Siltstone type)
Sandstone or Siltstone (common rock types that form river cobbles)
Quartz / Quartzite Fragment
Silicon Dioxide (SiO2)
River Pebbles (Sandstone and Quartzite)
SiO2 (Quartz) dominated clastic rocks
River Pebble (Quartzite/Siltstone mixture)
Silicon Dioxide (SiO2) mixture with varied clastic minerals