Snowflake Obsidian
Spherulitic Volcanic Glass (SiO2 + impurities)
igneous
Category
Man Made Rock Like Material
Browse man made rock like material specimens identified by the Rock Identifier community.
Blue Sapphire
Corundum (Al2O3)
mineral
Greenstone
Metabasalt / Greenschist facies rock
metamorphic
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Obsidian
Volcanic glass (high silica content based on SiO2)
igneous
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Phyllite
Phyllite
metamorphic
Sandstone (Ferruginous)
Arenite with Iron-oxide inclusions (SiO2 primarily)
sedimentary
Greenstone (Epidote/Chlorite Rich Rock)
Metabasalt (often contains Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH))
metamorphic
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and clay inclusions
sedimentary
Conglomerate
Polymictic Conglomerate
sedimentary
Agate (Moss or Dendritic Agate)
Chalcedony (Silicon Dioxide, SiO2)
mineral
Basalt
Basalt (Mafic Extrusive)
igneous
K2 Azurite Granite / K2 Stone
Granite (igneous rock) with Azurite inclusions (mineral)
igneous
Beach Pebble (Chert/Quartzite)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Grey Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Rhyolite
Rhyolite (High-silica volcanic rock)
igneous
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
Geode (Chert or Quartz Nodule)
Silicon Dioxide (SiO2)
sedimentary
Milky Quartz with Dendritic Inclusions
Silicon Dioxide (SiO2)
mineral
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chrysocolla
Hydrated copper silicates (Cu, Al)2H2Si2O5(OH)4·nH2O
mineral
Moss Agate
Chalcedony (Silicon Dioxide) with dendritic inclusions (SiO2)
mineral
Granitic Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Quartz (likely milky quartz or a stained variety)
Silicon Dioxide (SiO₂)
Mineral
Diamond (or Cubic Zirconia simulant)
Carbon (C) or Zirconium Dioxide (ZrO2)
mineral
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Red Sandstone (Siltstone/Mudstone variety)
Ferruginous Sandstone (composed primarily of Quartz with Hematite cementation)
sedimentary
Siltstone
Siltstone (primarily composed of microcrystalline Quartz and Feldspar)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
Mineral / Fossil
Red Jasper
Jasper (a variety of Chalcedony, SiO₂)
Mineraloid (cryptocrystalline quartz)
Chert (often called Flint when dark or worked)
Cryptocrystalline silica (SiO2)
sedimentary
Pink Granite
Phaneritic Plutonic Felsic Rock (rich in Potassium Feldspar)
igneous
Gneiss (Metamorphic Rock)
Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)
metamorphic
Sandstone (Quartzite texture)
Arenite (SiO2 secondary)
sedimentary
Orthoclase Feldspar
Potassium aluminum silicate (KAlSi3O8)
mineral
Chert (White Flint)
Silicon Dioxide (SiO2)
sedimentary
Scoria (Vesicular Basalt)
Scoria (Extrusive Igneous Rock)
igneous
Chert (Lightly weathered variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (Banded Variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Shale (Ferruginous)
Laminated Mudrock (Siliciclastic Sedimentary Rock)
sedimentary