Snowflake Obsidian
Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)
Igneous
Category
Mineral Based Human Made Alloy
Browse mineral based human made alloy specimens identified by the Rock Identifier community.
Glauconitic Sandstone (Greensand)
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
sedimentary
Slag (Industrial Glass Slag)
Amorphous Silica / Ferro-silicate Slag
mineraloid / anthropogenic
Granite
Phaneritic plutonic rock (Quartz, Alkali Feldspar, and Plagioclase)
igneous
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Granite
Phaneritic Plutonic Rock (High Silica content)
igneous
Sapphire (Corundum variety)
Sapphire (Al₂O₃)
Mineral
Mica Schist
Muscovite/Biotite Schist
metamorphic
Pink Granite
Granite (Phaneritic intrusive rock rich in K-feldspar)
igneous
Tree Agate
Silicon Dioxide (SiO2) with Chlorite/Manganese inclusions
sedimentary
Shale
Fissile Mudstone (primarily composed of clay minerals and quartz)
sedimentary
Chert (specifically Tan Chert)
Chert (SiO2)
sedimentary
Aquamarine
Beryl (Be3Al2Si6O18)
Mineral
Fuchsite
K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)
mineral
Muscovite Mica (likely on Quartz/Feldspar)
Muscovite - KAl2(AlSi3O10)(OH)2
mineral
Basalt with Quartz Vein
Basalt (SiO2 vein inclusion)
igneous
Conglomerate
Conglomerate (Detrital sedimentary rock)
sedimentary
Granite
Granite (Felsic Plutonic Rock)
igneous
Mica Schist with Iron Staining
Muscovite/Biotite Schist
metamorphic
Agate (or Banded Agate)
Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)
Mineral, specifically a Cryptocrystalline Quartz variety
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Metamorphic Rock
Cullet Glass (Man-made Glass Slag)
Amorphous Silica (SiO2) with chemical additives
Mineraloid
Brecciated Chert
Brecciated Chert (Microcrystalline Quartz, SiO2)
sedimentary
Dendritic Agate
Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2 + Mn/Fe)
mineral
Fuchsite Schist
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2) in Schist
metamorphic
Ruby in Zoisite (Anyolite)
Anyolite (Combination of Corundum and Zoisite)
metamorphic
Basalt (River Cobble)
Mafic Igneous Basalt (composed primarily of Plagioclase feldspar, Pyroxene, and Olivine)
Igneous
Mica Schist
Mica Schist
metamorphic
Granite
Granite (Silicic Plutonic Rock)
igneous
Granite
Granite (Felsic Plutonic Rock)
igneous
Basalt with Vesicle/Vug
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Vesicular Basalt
Basalt with secondary mineral infilling (Amygdaloidal Basalt)
igneous
Sagenitic Agate (with Goethite/Rutile inclusions)
Silicon Dioxide (SiO2) with hydrous ferric oxide inclusions
mineral
Basalt (Crushed Roadstone)
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Stichtite in Serpentine (Atlantisite)
Mg6Cr2CO3(OH)16·4H2O (Stichtite) / Mg3Si2O5(OH)4 (Serpentine)
metamorphic
Sandstone
Arenite (primarily Quartz, SiO2)
sedimentary
Basalt (with possible mineral veining)
Basalt (Aphanitic Mafic Igneous Rock)
Igneous
Schist
Mica Schist (Medium-grade Metamorphic Rock)
Metamorphic
Green Aura Quartz
Silicon Dioxide (SiO2) bonded with metallic vapors (typically Gold, Chromium, or Titanium)
mineral
Schist (Micaceous Schist)
Schist (comprising Muscovite/Biotite mica, Quartz, and Feldspar)
metamorphic
Mica Schist with Iron Staining
Mica Schist
metamorphic
Granite
Felsic Intrusive Igneous Rock
igneous