Faceted yellow-brown gemstone earring
Likely citrine (quartz, SiO₂), though treated quartz or synthetic glass cannot be confirmed from the image
gemstone
Category
Synthetic Or Natural Fiber
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Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Sedimentary Rock
Corundum
Corundum (Al2O3)
Mineral
Chalcedony Geode
Chalcedony (SiO2) within a geode structure
Mineral Geode/Sedimentary or Volcanic related
Man-made Crystal (Lead Glass)
Lead oxide-doped Silica Glass (approx. SiO2 + PbO)
Mineraloid/Synthetic Material
Blue opal heart cabochon
Common opal, hydrated amorphous silica (SiO₂·nH₂O), likely blue-dyed or synthetic opalite
gemstone
Banded sandstone pebble
Quartz-rich sandstone, likely arkosic or ferruginous sandstone
sedimentary
Concrete fragment or Conglomerate
Artificial Conglomerate (Concrete) or Natural Conglomerate
sedimentary
Quartz (Yellow/Citrine Variety)
Silicon Dioxide (SiO2)
mineral
Polymer Clay (Mock Mineral)
Polyvinyl chloride (PVC) with plasticizers and pigment
Synthetic material (Not a natural rock/mineral)
Basalt Pebble
Extrusive Igneous Rock
igneous
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Granite Pebble
Intrusive Igneous Rock
igneous
Granite Pebble
Intrusive Igneous Rock
igneous
Quartz (Iron-stained Quartz Pebble)
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Granite Pebble
Phaneritic intrusive igneous rock
igneous
Quartzite Pebble
Metamorphic Quartz-rich Rock
metamorphic
Red Quartzite Pebble
Quartzite (SiO2)
metamorphic
Lapis Lazuli
Lapis lazuli (complex rock; primarily Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(OH)₄(BO₃)₃Si₆O₁₈)
Mineral
Basalt with Weathered Surface
Basalt
Igneous
Quartz pebble
Silicon dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Hematite Pebble
Hematite (Fe2O3)
mineral
Quartzite Pebble
Quartzite
metamorphic
Pumice
Pumice (Felsic vesicular volcanic glass)
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Red Jasper Pebble
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
mineral
Sandstone Pebble
Sedimentary Rock (Quartzose Sandstone)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Flint / Chert
Silicon Dioxide (SiO2)
sedimentary
Jasper Pebble
Microcrystalline Quartz (Chalcedony), SiO2
sedimentary
Pink Quartz / Agate pebble
Silicon Dioxide (SiO2)
mineral
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Black Tourmaline (Schorl)
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
mineral
Bowling Ball (Brunswick T-Zone Deep Space)
Polyester resin / Polyurethane polymer
Synthetic (not a natural rock)
Quartz (Golden Quartz / Citrine / Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
River gravel and cobbles
Mixed alluvial clasts, likely including granite, basalt, quartzite, and sandstone
sedimentary
Polished white agate or chalcedony bead
Microcrystalline quartz (SiO₂), likely chalcedony/agate with iron-oxide staining or a brown mineral inclusion
gemstone
Kidney Stone
Calcium Oxalate (CaC2O4), Uric Acid, or Struvite
mineral