Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
igneous
Category
Man Made Byproduct (Often Mistaken For Obsidian Or Emerald)
Browse man made byproduct (often mistaken for obsidian or emerald) specimens identified by the Rock Identifier community.
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Obsidian
Obsidian (Volcanic Glass)
igneous
Obsidian
Obsidian (Amorphous volcanic glass)
igneous
Obsidian
Obsidian (Volcanic Glass)
igneous
Raw Emerald
Beryl (Be3Al2(SiO3)6) with Cr/V impurities
mineral
Diamond (Cut Gemstone)
Carbon (C)
gemstone
Sandstone
Arenite (mostly SiO2)
sedimentary
Gemstones (Emerald and Yellow Topaz or Citrine)
Beryl (Be3Al2Si6O18) and Quartz (SiO2) or Topaz (Al2SiO4(F,OH)2)
mineral
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Metamorphic Rock
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Obsidian
Obsidian (Volcanic Glass), primarily SiO2
igneous
Obsidian
Obsidian (Volcanic Glass)
igneous
Obsidian
Obsidian (Volcanic Glass)
igneous
Obsidian
Obsidian (Volcanic Glass)
igneous
Emerald in Matrix (Tumbled)
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
gemstone
Obsidian
Volcanic Glass (Amorphous SiO2)
igneous
Diopside (likely Chromian Diopside)
Diopside, part of Clinopyroxene family of inosilicates. Chemical formula: CaMgSi2O6. The green variety is often Chromian Diopside due to chromium impurities.
mineral
Peridot
Olivine ((Mg, Fe)2SiO4)
mineral
Obsidian flake
Volcanic glass; primarily silica-rich rhyolitic composition (approximately SiO₂)
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
mineraloid
Obsidian
Volcanic Glass
igneous
Obsidian
Obsidian (volcanic glass; primarily SiO2)
igneous
Sandstone
Arenite (with iron oxide cement)
sedimentary
Obsidian
Volcanic Glass (Amorphous SiO2)
igneous
Quartzite
Quartzite (SiO2)
metamorphic
Mixed Mineral Collection (with Quartz, Beryl, and host rock)
Silicon Dioxide (Quartz), Be3Al2Si6O18 (Beryl), and associated Schist/Pegmatite
mineral
Emerald in Matrix
Beryllium Aluminum Silicate (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Obsidian
Obsidian (principally SiO2)
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Obsidian
Obsidian (Volcanic Glass)
igneous
Peridot
Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)
mineral
Rough Diamond
Diamond (Pure Carbon: C)
mineral
Obsidian
Volcanic Glass (predominantly SiO2)
igneous
Obsidian
Volcanic Glass (mostly SiO2)
igneous
Granodiorite with Quartz Veining
Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins
igneous
Obsidian
Volcanic Glass (Amorphous Silica)
igneous
Obsidian
Volcanic Glass (SiO2 rich)
igneous
Obsidian
Obsidian (Volcanic Glass)
igneous
Serpentine
Serpentinite (a rock composed primarily of serpentine minerals like antigorite, chrysotile, and lizardite; general formula (Mg, Fe)3Si2O5(OH)4)
metamorphic
Fuchsite or Green Mica Schist
Muscovite variant (KAl2(AlSi3O10)(OH)2 with Cr)
metamorphic
Green Fuchsite and Quartz
K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)
metamorphic