White Opal
Hydrated Silica (SiO2·nH2O)
mineral
Category
Mineraloid (Man Made Origin)
Browse mineraloid (man made origin) specimens identified by the Rock Identifier community.
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Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
igneous
Turquoise Beads
CuAl6(PO4)4(OH)8·4H2O
gemstone
Obsidian
Obsidian (volcanic glass, amorphous silica rich rock)
Igneous
Limestone Gravel
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Pearl
Organic Mineraloid (CaCO3 + Conchiolin)
mineral
Polished mahogany obsidian (probable)
Volcanic glass; chiefly rhyolitic silica-rich glass (SiO₂), compositionally near rhyolite
igneous
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
igneous
Obsidian
Volcanic Glass (Amorphous SiO2)
igneous
Obsidian
Volcanic Glass (SiO2 rich)
igneous
Fulgurite
Fulgurite (Lechatelierite-rich fused silica)
mineraloid / sedimentary (secondary formation)
Chondrite Meteorite
Ordinary Chondrite (Undifferentiated Stony Meteorite)
meteorite
N/A - Man-made object (Jewelry Chain)
Antiqued or Oxidized Metal Chain (often Steel or Brass)
Mineral (processed metal)
Man-made Jewelry Charm (Enameled Metal)
Not a natural mineral; composed of base metal alloy (likely zinc or brass) and epoxy resin/enamel.
Synthetic / Manufactured Artifact
Fossil bivalve shell
Likely an internal mold or mineralized shell of a brachiopod or small bivalve; exact taxonomy requires locality and diagnostic details
fossil
Amber
Fossilized tree resin (Amorphous organic polymer)
gemstone
Abalone Shell (Nacre)
Aragonite (CaCO3) - Biogenic Mineral
mineral
Limonite/Goethite on Shale
Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock
sedimentary
Fluorite
Calcium fluoride (CaF2)
mineral
Fluorite on Matrix
Calcium Fluoride (CaF2)
mineral
Fluorite Cleavage Octahedron
Fluorite (Calcium Fluoride, CaF2)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite on Matrix
Calcium Fluoride (CaF2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Amber with Inclusion
Succiniferous fossil resin (C10H16O)
mineraloid
Native Silver
Silver (elemental Ag)
mineral
Pearl
Calcium Carbonate (CaCO3) - mainly Aragonite and Calcite
mineral
Emerald
Beryl (Be3Al2(SiO3)6) with chromium/vanadium impurities
mineral
Pearl (incorporated into jewelry)
Aragonite and Calcite (CaCO3)
mineral
Chondrite Meteorite
Ordinary Chondrite (L or H group)
meteorite
Chondrite Meteorite
Ordinary Chondrite (L or H group)
igneous
Chondrite Meteorite
L or H type Ordinary Chondrite
igneous
Obsidian
Volcanic Glass (70% or more SiO2)
igneous
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Igneous
Amber in Matrix
Succinite (Carbon-based organic polymer)
Organic (Sedimentary context)
Obsidian
Obsidian (Amorphous volcanic glass, predominantly SiO2)
igneous