Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
Category
Browse synthetic glass specimens identified by the Rock Identifier community.
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2)
Smoky Quartz
Silicon Dioxide (SiO₂)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Chert or chalcedony fragment
Microcrystalline quartz (SiO₂), possibly jasper or agate
Pale blue-gray quartz-rich pebble (tentative)
Quartz, SiO₂, possibly chalcedony or a weathered metamorphic fragment
Quartz (Milky Quartz / Quartz Crystal)
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Tumbled Agate and Chalcedony
Cryptocrystalline Quartz (SiO2)
Chert (Flint variety)
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with traces of titanium, iron, or manganese
Yellow Quartz / Citrine Quartz
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace Titanium, Manganese, or Iron
Quartzite
Quartzite (SiO2)
Polished blue calcite sphere (tentative identification)
Calcite, CaCO₃; blue color generally results from trace impurities or inclusions
Quartz-rich metamorphic rock, likely quartzite
Quartzite; predominantly crystalline quartz (SiO₂), possibly with mica and feldspar
Smoky Quartz
Silicon Dioxide (SiO2)
Snowflake Obsidian
Hydrated Volcanic Glass (primarily SiO2) with Cristobalite inclusions
Gray Quartz (Tumbled)
Silicon Dioxide (SiO2)
Faceted Quartz (Rock Crystal)
Crystalline Silicon Dioxide (SiO2)
Snowflake Obsidian
Volcanic Glass with Spherulite Inclusions (70-75% SiO2)
Fulgurite
Liesegang (Fulgurite)
Sea Glass (often mistaken for Gemstones)
Amorphous Silica (SiO2) with trace additives
Quartz Pebble
Silicon Dioxide (SiO2)
Tumbled yellow quartz (likely citrine or iron-stained quartz)
Quartz, silicon dioxide (SiO₂); yellow coloration likely from iron impurities
Tumbled reddish sandstone pebble
Quartz-rich sandstone, likely ferruginous arkose or quartz arenite
Quartz with Mica / Chlorite Inclusion
Silicon Dioxide (SiO2) with Phyllosilicate minerals
Iron-Stained Quartz (Red/Hematoid Quartz)
Silicon Dioxide (SiO2) with Hematite/Goethite inclusions
Jasper
Jasper (Cryptocrystalline variety of Quartz, SiO2)
Chert (specifically Gray/Black Chert)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
Feldspar in Matrix
Feldspar group minerals in metamorphic or igneous matrix
Quartz Crystal
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz pebble
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Arenite (SiO2 primarily)
Fulgurite
Lechatelierite (Silica glass tube)
Fulgurite
Lechatelierite (Silica glass tube)
Clear quartz sphere
Quartz (silicon dioxide, SiO₂)