Black Obsidian
Obsidian (Volcanic Glass)
Category
Browse mineral and glass specimens identified by the Rock Identifier community.
Black Obsidian
Obsidian (Volcanic Glass)
Chert (Jasper variation)
Chert (Silicate mineral, SiO2)
Quartzite Pebble
Quartzite (SiO2) with mineral inclusions
Quartz Pebble
Silicon Dioxide (SiO2)
Small pale rock fragment
Indeterminate; possibly quartz, calcite, or a weathered feldspar-rich fragment
Quartz
Silicon Dioxide (SiO2)
Potassium Feldspar and Quartz
KAlSi3O8 (Potassium Feldspar) and SiO2 (Quartz)
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
Tumbled Aventurine
Silicon Dioxide with inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Green Aventurine
SiO2 (Quartz with Fuchsite inclusions)
Quartz (Agate/Chalcedony)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Faceted Quartz (Rock Crystal)
Crystalline Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Chert / Flint
Chert (Silicon Dioxide, SiO2)
Sandstone
Arenite (primarily Quartz, SiO2)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Arenite (SiO2 based)
Quartz geode
Microcrystalline and crystalline quartz (SiO₂), likely chalcedony-lined geode
White Quartz
Silicon Dioxide (SiO2)
Milky quartz (quartz-rich rock fragment)
Quartz, silicon dioxide (SiO₂)
Clear Quartz
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Clear Quartz
Silicon dioxide (SiO2)
Cloudy Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz / Quartzite Fragment
Silicon Dioxide (SiO2)
Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
Opalite
Synthetic Opalized Glass
Granitic Pegmatite (with Pink Feldspar and Quartz)
Pegmatite (KAlSi3O8 + SiO2)
Jasper
Microcrystalline Quartz (SiO2) with impurities
Botryoidal Quartz or Chalcedony
Silicon Dioxide (SiO2)
Quartz Druzy
Silicon Dioxide (SiO2)
Quartz (with inclusions / Sandstone fragment)
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Quartz (Pebble)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (SiO2)
Red Jasper and Green Aventurine
Silicon dioxide (SiO2)
Quartz pebble
Silicon dioxide (SiO2)
Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2)
Smoky Quartz
Quartz (Silicon Dioxide) - SiO2