Polished black stone egg, probably black obsidian
Obsidian, a natural volcanic glass; composition primarily silica-rich glass (approximately SiO₂), with variable iron and other trace elements
gemstone
Category
Man Made Object (Ring)
Browse man made object (ring) specimens identified by the Rock Identifier community.
Learn about Man Made Object (Ring) in the encyclopedia
View all →
Dalmatian Stone
Dalmatian Jasper (a misnomer for an Aplite with Arfvedsonite spots)
igneous
Sea Glass
Amorphous silicon dioxide (man-made glass weathered by nature)
mineral
Slag
Anthropogenic Vitreous Silica/Iron oxides
mineral-like byproduct
Asphalt Chunk (Bituminous Concrete)
Aggregated Bitumen / Artificial Breccia
sedimentary
Felsic Drill Core (likely Gneiss or Granite)
Felsic Metamorphic Rock (Gneissic profile)
metamorphic
Concrete with Exposed Aggregate
Anthropogenic conglomerate (Concrete)
man-made rock (sedimentary analogue)
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2AlSi3O10(OH)2)
metamorphic
Ironstone Concretion (Pot Stone)
Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)
sedimentary
Crackled Quartz (Dyed)
Silicon Dioxide (SiO2)
mineral
Engineerged Quartz (Quartz Composite)
SiO2 (Silicon Dioxide) in a polymer resin matrix
mineral
Porcelain (White Ceramic)
Mullite-bearing Vitrified Ceramic (Major phases: Mullite Al6Si2O13, Glassy Silica SiO2)
metamorphic
Acrylic or Resin (Synthetic Imitation)
Polymethyl Methacrylate (PMMA) or Polyepoxide
Synthetic/Man-made Polymer
Green Sea Glass
Man-made silicate glass (weathered)
sedimentary
Blue Slag Glass
Man-made Silicon Dioxide (Amorphous)
Anthropogenic (Man-made)
Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Mineraloid
Concrete Fragment
Hardened Portland Cement Composite
Anthropogenic (Man-made material mimicking sedimentary rock)
Green Aventurine
SiO2 (Silicon Dioxide with Fuchsite inclusions)
mineral
Slag
Anthropogenic glassy silicate
Mineral-like byproduct
Sandstone-based Concrete Fragment
Cementitious Composite with Sedimentary Aggregate
sedimentary (man-made/anthropogenic)
Aura Quartz Geodes (Lab-Altered)
Silicon Dioxide (SiO2) with Metallic Vapor Deposition
mineral
Opalite
Man-made Glass (SiO2 + additives)
mineraloid (synthetic)
Diamond
Carbon (C)
gemstone
Ocean Jasper Mushroom
Orbicular Jasper (Silicon Dioxide, SiO2 mixed with various impurities)
mineral
Blue Goldstone
Aventurine Glass
man-made glass
Diamond (or Diamond Simulant)
Carbon (C)
mineral
Opalite
Synthetic Opalite (Man-made glass)
mineral
Dyed Imperial Jasper (Sea Sediment Jasper)
Silicon Dioxide (SiO2) - Impure Quartz/Chalcedony
sedimentary
Opalite
Synthetic Glass (SiO2 + impurities)
mineral
Opalite
Synthetic Glass (typically Silica/Magnesium based with metal additives)
mineral
Silicon Carbide (Carborundum)
Silicon Carbide (SiC) / Moissanite (natural)
mineral
Asphalt (Bituminous pavement)
Bituminous concrete / Asphalt
Sedimentary (Anthropogenic)
Titanium-Coated Hematite (Aura Hematite)
Titanium-bonded Hematite (Fe2O3 with a Ti coating)
mineral
Bismuth Crystal
Bismuth (Bi)
mineral
Aura Rose Quartz
SiO2 (Silicon Dioxide with Titanium/Gold coating)
mineral
Asphalt (Bituminous Concrete)
Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)
not a rock (anthropogenic material/technofossil)
Cubic Zirconia
Cubic Zirconium Dioxide (ZrO2)
gemstone
Aura Quartz (Titanium-coated Quartz)
Silicon Dioxide (SiO2) with metallic vapor coating
mineral
Sandstone Concretion
Clastic Sedimentary Concretion (SiO2 with Iron Oxide)
sedimentary
Titanium Aura Quartz
Titanium-coated Silicon Dioxide (SiO2)
mineral
Crackle Agate / Dyed Quartz
SiO2 (Silicon Dioxide)
mineral
Blue Goldstone
Man-made glass with cobalt and metal flecks
man-made glass