Quartz pebble
Silicon Dioxide (SiO2)
mineral
Category
Industrial Byproduct (Often Mistaken For Obsidian Or Mineral)
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Red Quartz (Druzy)
Silicon Dioxide (SiO2) with Hematite inclusions
mineral
Snowflake Obsidian
Vitreous Volcanic Rock (Amorphous Silicate), SiO2
igneous
Strawberry Quartz
Silicon Dioxide (SiO2) with inclusions of Goethite or Hematite
Mineral
Black Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
igneous
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
mineral
Scoria
Vesicular Basalt / Scoriaceous Basalt
igneous
Serpentine
Serpentinite (rock), Serpentine group minerals (e.g., Antigorite, Lizardite, Chrysotile)
Metamorphic rock
Apache Tears (Obsidian)
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
igneous
Raw Diamond (Rough Uncut)
Diamond (C - pure carbon)
mineral
Agate (Chert/Chalcedony)
Silicon Dioxide (SiO2)
mineral
Clear Quartz (Tumbled)
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
White Topaz
Aluminum Silicate Fluoride Hydroxide; Al2SiO4(F,OH)2
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Snowflake Obsidian
Spherulitic Obsidian (Amorphous volcanic glass with Phenocrysts of Cristobalite)
igneous
Amygdaloidal Basalt
Amygdaloidal Basalt
igneous
Gold-bearing Quartz
Native Gold (Au) in Quartz (SiO2) matrix
mineral
Jasper
Jasper / Silicon Dioxide (SiO₂)
sedimentary
Turquoise and Hematite
CuAl6(PO4)4(OH)8·4H2O (Turquoise) and Fe2O3 (Hematite)
mineral
Blue Apatite
Apatite - Ca5(PO4)3(F,Cl,OH) (Calcium phosphate with Fluorine, Chlorine, or Hydroxyl)
mineral
Snowflake Obsidian
Volcanic glass containing Spherulite inclusions (primarily Cristobalite, SiO2)
igneous
Quartz / Common Opal Transition
Silicon Dioxide (SiO2)
mineral
Quartz (Water-worn pebble)
Silicon Dioxide (SiO2)
mineral
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Sedimentary
Rhyolite
Rhyolite (Extrusive Felsic Igneous Rock)
igneous
Opalite (Man-made Glass)
Synthetic Opalised Glass
mineral
Silver (Native or Alloyed)
Ag (Argentum)
mineral
Mahogany Obsidian
Obsidian (Volcanic Glass with Hematite/Magnetite inclusions), SiO2
igneous
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Quartz Druze on Matrix
Silicon Dioxide (SiO2)
mineral
Jasper
Jasper (Silica/Silicon Dioxide, SiO2)
sedimentary
Quartz Pebble (Water-worn Quartzite)
Silicon Dioxide (SiO2)
metamorphic
Chlorite (Small Flakes/Sand)
Chlorite Group (Magnesium Iron Aluminum Silicate Hydroxide - (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)
mineral
Tumbled Obsidian (possibly Mahogany Obsidian variant)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
igneous
Basalt
Basalt (composition predominately plagioclase feldspar and pyroxene)
igneous
Agate Nodule / Weathered Chert
SiO2 (Silicon Dioxide - Microcrystalline Quartz)
Sedimentary / Mineral
Note regarding image quality
Indeterminate
Cupronickel (on a 1981 Mexico 20 Pesos coin)
Copper-Nickel Alloy (Cu75Ni25)
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Asphalt Concrete (Bituminous Concrete)
Bituminous aggregate
sedimentary
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
igneous