Amethyst (Rose de France)
Silicon Dioxide (SiO2) with iron impurities
mineral
Category
Synthetic Glass
Browse synthetic glass specimens identified by the Rock Identifier community.
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Snowflake Obsidian
Obsidian with Cristobalite inclusions (Amorphous SiO2 + SiO2 inclusions)
igneous
Small polished dark mineral or gemstone fragment
Indeterminate; possibly smoky quartz, obsidian, or dark tourmaline
mineral
Pumice (with oxidation)
Pumice (Vitreous pyroclastic rock)
igneous
Snowflake Obsidian
Volcanic Glass with Spherulite inclusions (Chemical composition: 70–75% SiO2 + MgO, Fe3O4)
igneous
Celadonite in Amygdaloidal Basalt
K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2 (Celadonite mineral) within a Basalt matrix
igneous
Tektite (Indochinite)
Tektite (Natural Glass, SiO2 + Al2O3)
mineral
Apache Tears (Obsidian)
Hydrated Volcanic Glass (Amorphous SiO2 + H2O)
igneous
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
igneous
Quartz crystal point (likely smoky or iron-stained quartz)
Quartz, silicon dioxide (SiO₂)
mineral
Quartzite
Quartzite (composed primarily of Quartz, SiO2)
metamorphic
Quartzite
Quartzite (90%+ SiO2)
metamorphic
Clear Quartz Crystal
Silicon Dioxide (SiO2), Quartz
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Smoky Quartz (Rough)
Silicon Dioxide (SiO2)
mineral
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartzite (Coldwater or Druzy Quartz over Quartzite)
SiO2 (Silicon Dioxide)
metamorphic
Diamond / Clear Quartz / Glass paste
Carbon (Diamond) / Silicon Dioxide (Quartz)
gemstone
Tektite (Indochinite)
Impactite / Tektite (Silica-rich glass)
igneous
Obsidian
Obsidian
Igneous
Milky Quartz
Quartz (Silica / Silicon Dioxide), SiO2
mineral
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
metamorphic
Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Pumice
Pumice (Vesicular Felsic Igneous Rock)
igneous
Pumice
Pumice (Amorphous silicate glass with trapped gas bubbles)
igneous
Tektite (Indochinite)
Tektite (High-silica impactite glass)
meteorite
Obsidian (Polished)
Obsidian (Volcanic glass, primarily SiO2)
igneous
Tektite (Indochinite)
Tektite (High-silica impact glass)
igneous