Rough Sapphire (Corundum)
Corundum (Al2O3)
mineral
Category
Anthropogenic (Man Made Material)
Browse anthropogenic (man made material) specimens identified by the Rock Identifier community.
Pumice
Pumice (Vitreous volcanic rock)
igneous
Obsidian
Volcanic Glass (70% or more SiO2)
igneous
Pumice
Pumice (Vesicular volcanic glass)
Igneous
Sandstone Concretion
Sedimentary concretion
Sedimentary
Blue Lace Agate
Chalcedony (SiO2) with trace inclusions
mineral
Gold (Elemental Metal)
Gold (Au)
Mineral
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide)
igneous
Chalk
CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock
Sedimentary
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
igneous
Granite
Plutonic Igneous Rock (composed typically of SiO2, Al2O3, K2O, Na2O, CaO)
igneous
Beaded Jewelry (Assorted Gemstones)
Various minerals, including but not limited to Quartz (SiO2), Garnet (X3Y2(SiO4)3), Jade (Na(Al,Fe)Si2O6), Amethyst (SiO2),等の多様な組み合わせ
Mineral, Jewelry
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Sedimentary
Sea Glass
Amorphous Silica (SiO2) with various additives
Mineraloid (Anthropogenic)
Mixed Gemstone Beaded Jewelry
Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)
Mineral
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Diabase (Greenstone)
Diabase (also known as Dolerite)
igneous
Chert / Flint
Chert (varieties include Flint)
Sedimentary
Quartz (Engineered Quartz Surface)
Silicon Dioxide (SiO2) based composite
mineral (man-made composite)
Obsidian
Obsidian (volcanic glass, amorphous silica rich rock)
Igneous
Chert
Chert (microcrystalline quartz)
sedimentary
Granite
Phaneritic Felsic Igneous Rock
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite
sedimentary
Granite
Granite (Phaneritic Quartz-Feldspar intrusive rock)
Igneous
Diamond
Cubic carbon (C)
mineral
Bog Iron / Limonite Concretion
Goethite/Limonite mixture (FeO(OH)·nH2O)
sedimentary
Slag Glass
Amorphous Silica / Glass Slag
industrial byproduct (anthropogenic rock-like material)
Pearl
Biogenic CaCO3 (Aragonite and Calcite)
mineral
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)
Quartzite
Metamorphic Rock (Mainly SiO2)
metamorphic
Turquoise
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
mineral
Blue Goldstone
Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)
Synthetic (Man-made Glass)
Cullet Glass (Strawberry Glass)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Mineraloid (Synthetic/Man-made)
Paper (Cellulose)
Cellulose (C6H10O5)n
Organic (Anthropogenic)
Slag (Industrial Glass Slag)
Amorphous Silica / Ferro-silicate Slag
mineraloid / anthropogenic
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Smoky Quartz
Smoky Quartz (SiO2)
mineral
Pearl
Organic gemstone (Calcium carbonate - CaCO3)
mineral
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
mineraloid
Diamond (in a jewelry setting)
Cubic Carbon (C)
mineral
Obsidian
Volcanic Glass (SiO2)
igneous