Scoria (Lava Rock)
Scoria (extrusive volcanic rock)
igneous
Category
Man Made Object (Ring)
Browse man made object (ring) specimens identified by the Rock Identifier community.
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Petrified Wood
Silicified Wood (primarily quartz/chalcedony replacing organic wood structures, SiO2)
fossil
Ruby ring (likely synthetic ruby)
Corundum, Al₂O₃; red color from chromium. The image alone cannot establish whether the stone is natural or lab-grown.
gemstone
Eye Agate
Chalcedony (SiO2)
sedimentary
Crinoid Columnal Fossil
Crinoid ossicle (Class Crinoidea)
sedimentary
Likely rough pink feldspar or rose quartz
Most likely microcline feldspar (KAlSi₃O₈) or rose quartz (SiO₂)
mineral
Polished black obsidian
Volcanic glass; primarily rhyolitic SiO₂, with minor iron, magnesium, and other trace elements
igneous
Amethyst cabochon jewelry
Amethyst, purple variety of quartz (SiO₂)
gemstone
Bloodstone
Chalcedony (cryptocrystalline quartz)
Mineral/Semiprecious Stone
Carnelian
Carnelian (a variety of Chalcedony, SiO ₂)
Mineral (specifically a variety of Chalcedony, which is a cryptocrystalline quartz)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Carnelian
Carnelian (a variety of Chalcedony, SiO₂)
Mineral
Jadeite Jade
Jadeite (NaAlSi2O6)
metamorphic
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Colorless faceted gemstone, likely glass or cubic zirconia
Uncertain; possible cubic zirconia (ZrO₂) or quartz (SiO₂), but the image may show a man-made simulant
gemstone
Colorless faceted quartz-like gemstone
Likely quartz (SiO₂), though the appearance may also indicate man-made glass or cubic zirconia
gemstone
Jasper
Silicon Dioxide (SiO2) microcrystalline quartz
sedimentary
Fossiliferous wood / petrified wood fragment
Silicified or partially mineralized wood (fossil wood; commonly quartz/chalcedony replacement)
fossil
Diamond
Carbon (C)
gemstone
Blue Sapphire and Diamond (Set in Metal)
Corundum (Al2O3) and Diamond (C)
mineral
Cubic Zirconia (CZ)
Cubic Zirconium Dioxide (ZrO2)
mineral (synthetic)
Nephrite Jade Ring
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)
gemstone
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Polished petrified wood
Silicified wood; commonly quartz/chalcedony (SiO₂) replacing wood tissue
fossil
Botryoidal chalcedony with quartz vug
Microcrystalline quartz, SiO₂ (chalcedony), with a drusy quartz-lined cavity
mineral
Quartz cabochon ring (stone identity uncertain)
Quartz, SiO₂ (possible smoky or included quartz)
gemstone
Polished petrified wood (agate/chalcedony replacement)
Silicified wood, chiefly microcrystalline quartz (SiO₂), often with iron-oxide coloration
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Terrazzo (with Marble and Granite fragments)
Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates
sedimentary (man-made composite)
Diamond (in a jewelry setting)
Carbon (C)
mineral
Tumbled purple chalcedony or low-grade amethyst bead bracelet
Chalcedony (microcrystalline SiO₂), possibly quartz/amethyst; composition is SiO₂
mineral
Fossiliferous Flint or Chert with Bryozoan Fossils
Sedimentary cryptocrystalline quartz (SiO2) with fossil inclusions
sedimentary
Diamond
Native Carbon (C)
mineral
Red Jasper
Silicon Dioxide (SiO2)
sedimentary
Fossilized bivalve shell
Bivalvia indeterminate; likely a fossil clam or cockle
fossil
Red Jasper Cube
SiO2 (microcrystalline quartz)
mineral
Worn River Pebble with Fossil Indentation
Sedimentary Rock with Fossil Infill
sedimentary
Petrified Wood
Silicified Wood / Xylopal (SiO2)
fossil
Red-and-brown agate bead bracelet
Agate, a microcrystalline variety of quartz (SiO₂), likely colored chalcedony/carnelian
mineral
Crinoid Marble
Crinoidal Limestone/Marble
fossil
Crinoid Stem Fossil
Crinoidea (Class) - Calcium Carbonate (CaCO3)
fossil
Pumice
Pumice (Amorphous volcanic glass)
igneous