Limonite (Iron Ore)
Limonite; FeO(OH)·nH2O
Category
Browse synthetic glass (man made) specimens identified by the Rock Identifier community.
Limonite (Iron Ore)
Limonite; FeO(OH)·nH2O
Diamond (in a jewelry setting)
Diamond (Carbon, C)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Chert / Flint Variety)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
Gold and Cubic Zirconia (San Judas Tadeo Pendant)
Native Gold (Au) with Synthetic Cubic Zirconia (ZrO2)
Smoky Quartz
Silicon dioxide with aluminum impurities (SiO2)
Red Slag Glass (Cullet)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
Chert (Cherty Shale / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Slag (Industrial Glass/Metal)
Ferrous slag or Glassy silicate byproduct
Hematite
Iron(III) oxide (Fe2O3)
Dyed Alum or Dyed Quartz (Ornamental Crystal)
Silicon Dioxide (SiO2) or Potassium Alum [KAl(SO4)2·12H2O]
Malaysian 50 Sen Coin
Coinage (specific alloy unknown without metallurgical analysis, but typically brass or bronze for this denomination and era)
Rough Corundum (likely Sapphire or Common Corundum)
Aluminum oxide (Al2O3)
Chert
Silicon dioxide (SiO2)
Smoky Quartz
Smoky Quartz (SiO2)
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (70–75% SiO2)
Quartzite
Metamorphic Rock (Mainly SiO2)
Chert (Polished River Pebble)
Chert (SiO2)
Diamond (or Cubic Zirconia)
Crystallized Carbon (C) for Diamond; Zirconium Dioxide (ZrO2) for CZ
Note: The image provided is a fabric sock, not a geological specimen.
Polyester-Cotton Blend with Elastane
Synthetic Ruby (Jewel Bearings)
Synthetic Corundum (Al2O3 doped with Chromium)
Sandstone
Arenite
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Obsidian (Black)
Obsidian (High-silica volcanic glass)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Diamond in Kimberlite
Diamond (C in Kimberlite)
Smoky Quartz
Silicon Dioxide (SiO2) with trace aluminum and irradiation
Diamond (in jewelry setting)
Diamond (C - Carbon)
Chert / Flint
Silicon Dioxide (SiO₂)
Chert
Chert (SiO2)
Chert (often called Flint in archaeological contexts)
Silicon Dioxide (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Lapis Lazuli
A metamorphic rock primarily composed of lazurite (Na,Ca)8[(S,SO4,Cl)2|(Al6Si6O24)], calcite (CaCO3), and pyrite (FeS2).
Blue Sapphire (in a faceted jewelry setting)
Corundum (Al2O3) with trace Iron and Titanium
Ruby
Corundum (Al2O3 with Chromium)
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (varietal Chalcedony or Flint)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Blue Sapphire
Corundum (Al2O3) with traces of Iron and Titanium
Chert (with Limestone matrix)
Silicon dioxide (SiO2)