Assorted Semi-Precious Gemstone Crosses
Quartz, Silicates, Carbonates (various)
mineral
Category
Synthetic (Man Made Glass)
Browse synthetic (man made glass) specimens identified by the Rock Identifier community.
Quartzite (River Pebble)
Quartzite (Mainly SiO2)
metamorphic
Lava Stone and Chakra Beads
Basalt (with various mineral/synthetic beads)
igneous
Slag (Industrial Byproduct)
Ferro-silicate glass (Slag)
Anthropogenic (Man-made industrial deposit)
K2 Stone (or K2 Jasper)
Azurite-in-Granite (Potassium Feldspar, Quartz, Plagioclase, Muscovite, and Azurite)
igneous
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
mineral
Dyed Agate
Silicon Dioxide (SiO2) - variety Chalcedony
mineral
Slag Glass (Cullet)
Amorphous Silica / Glass residue
Man-made byproduct (Non-geological)
Blue Sapphire
Corundum (Al2O3)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Chert (varieties include Flint and Mudstone)
Microcrystalline Silica (SiO2)
sedimentary
Green Glass Cullet / Recycled Glass
Amorphous Silicon Dioxide (SiO2) with various metal oxides
Man-made Glass (Not a natural rock or mineral)
Moissanite
Silicon Carbide (SiC)
mineral
Diamond
Carbon (C)
mineral
Rough Corundum (Sapphire/Ruby mixture)
Corundum (Aluminum Oxide, Al2O3)
mineral
Diamond (Colorless/White)
Carbon (C)
mineral
Ruby (Pink to Red Corundum)
Al2O3 (Corundum with Chromium impurities)
mineral
Ruby
Corundum (Al2O3 with Chromium traces)
mineral
Sandstone (likely Quartzose Sandstone)
Arenite
sedimentary
Iron Slag
Ferrous slag (primarily silicates and oxides of calcium, iron, and magnesium)
Anthropogenic (Man-made industrial byproduct)
Chert (variations include Flint/Novaculite)
Chert (formula: SiO2)
sedimentary
Borosilicate Glass (Manufactured)
SiO2 + B2O3 (Silicon dioxide and Boron trioxide)
Synthetic/Amorphous Solid
Pearl
Pearl (Calcium Carbonate with organic conchiolin, CaCO3)
mineral
Chert (Common Variety, Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint)
Chert (SiO2)
sedimentary
Chalk
Micrite (primarily Calcium Carbonate, CaCO3)
sedimentary
Emerald
Beryl (Be3Al2Si6O18), specifically the green variety colored by chromium or vanadium
Mineral (Gemstone variety of Beryl)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
mineral
Obsidian
Volcanic Glass (Amorphous SiO2)
igneous
Diamond (in a jewelry setting)
Carbon (C)
mineral
Ruby
Corundum (Al2O3 with Chromium traces)
mineral
Bituminous Coal
Organic-rich sedimentary rock (Complex hydrocarbons)
sedimentary
Amethyst (Tumbled/Weathered Quartz)
Amethyst (SiO2 with iron impurities)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Chert (Common Opal/Jasper variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Pink Dyed Agate
Silicon Dioxide (SiO2) with synthetic pigment
mineral
Dyed Quartzite
Metamorphosed Quartz (SiO2) with synthetic pigment
metamorphic
Dyed Agate
Silicon Dioxide (SiO2) with synthetic dyes
mineral
Smoky Quartz Cluster
Smoky Quartz (Silicon Dioxide - SiO2)
mineral
Ametrine
Ametrine (SiO2 - Silicon Dioxide with trace amounts of Iron)
mineral
Chert (often called Flint or Agate nodule)
Cryptocrystalline Quartz (SiO2)
sedimentary
Zircon
Zirconium Silicate (ZrSiO₄)
mineral