Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
mineral
Category
Man Made Byproduct (Often Mistaken For Obsidian Or Emerald)
Browse man made byproduct (often mistaken for obsidian or emerald) specimens identified by the Rock Identifier community.
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Black Obsidian
Obsidian, volcanic glass (Amorphous SiO₂)
Igneous Rock
Chert (often called Flint)
Chert (Microcrystalline or cryptocrystalline Silica, SiO2)
sedimentary
Ruby
Corundum (mineral species), variety: Ruby (Al2O3 with Cr3+ as the chromophore)
Mineral
Chert (specifically Flint)
Chert (SiO2)
sedimentary
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Pyrite on Limestone
Iron Disulfide (FeS2) in Calcium Carbonate (CaCO3) matrix
sedimentary (matrix) / mineral (inclusion)
Jasper (Iron-rich Chalcedony)
Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)
Sedimentary / Metamorphic
Diabase (Greenstone)
Diabase (also known as Dolerite)
igneous
Black Onyx
Silicon Dioxide (SiO2) with cryptocrystalline structure
mineral
Bryozoan Fossil
Phylum Bryozoa (commonly known as 'moss animals')
sedimentary
Wild Horse Magnesite
Magnesite with Hematite inclusions (MgCO3)
mineral
Scoria
Vesicular Basalt / Scoriaceous Basalt
igneous
Apache Tears (Obsidian)
Hydrated Volcanic Glass (Amorphous SiO2 + H2O)
igneous
Sandstone Concretion
Ferruginous Sandstone Concretion
sedimentary
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with inclusions of Hematite or Magnetite)
igneous
Chert (with Limestone matrix)
Silicon dioxide (SiO2)
sedimentary
Greenstone
Greenschist (primarily composed of chlorite, actinolite, and epidote)
metamorphic
Chert (Nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Rhyolite
Rhyolite
igneous
Bismuth
Bismuth (Bi)
mineral
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
igneous
Ferruginous Sandstone (Ironstone)
Sedimentary rock with high iron oxide content (Fe2O3 / FeO(OH))
sedimentary
Apache Tear (Obsidian)
Hydrated volcanic glass (SiO2 with inclusions)
igneous
Banded Slate (Lithified Mudstone)
Low-grade Metamorphosed Mudstone / Slate
metamorphic
Apache Tear
Hydrated Obsidians (Volcanic Glass)
igneous
Horse Chestnut (Buckeye seed)
Aesculus hippocastanum seed
Organic (Non-geological)
Unakite (bottom) and Sodalite (top)
Epidotized Granite (Unakite) and Sodium Aluminum Silicate Chloride (Sodalite)
metamorphic
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Coquina
Bioclastic Limestone (Coquina)
sedimentary
Chert
Silicon dioxide (SiO2)
Sedimentary
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Sandstone Concretion
Clastic Sedimentary Concretion (primarily SiO2 with Fe2O3 cement)
sedimentary
Granitic Sand
Detrital sediment (predominantly Quartz, Feldspar, and Mica)
sedimentary
Sodalite
Na8(Al6Si6O24)Cl2
mineral
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
sedimentary
Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite
mineral
Garnet (Pyrope-Almandine series)
Garnet Group, (Mg,Fe)3Al2Si3O12
mineral
Lapis Lazuli
Lapis Lazuli (Primary mineral: Lazurite, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Chrysoprase
Silicon Dioxide (Nickel-bearing Chalcedony) - SiO2
mineral