Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
Category
Browse mineral and metamorphic rock specimens identified by the Rock Identifier community.
Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
Anthracite Coal
Low-grade metamorphic carbonaceous rock
Gneiss
High-grade foliated metamorphic rock
Quartzite River Cobble
Quartzite (primarily SiO2)
Ferruginous Quartzite (Iron-stained Quartzite)
Quartzite with Iron oxides (FeO(OH) / Fe2O3)
White Quartz
Quartz (SiO2)
Marble
Metamorphosed Limestone/Dolomite
Green Aventurine and Clear Quartz
Green Aventurine (Silicon Dioxide - SiO2 with Fuchsite inclusions); Clear Quartz (Silicon Dioxide - SiO2)
Schist
Schist
Quartzite pebble
Quartzite (SiO2)
White Marble
Recrystallized Calcite (CaCO3) / Marble
White Quartzite
Quartzite (primarily SiO2)
Unakite
Epidotized Granite
Serpentinite
Serpentinite (composed primarily of serpentine group minerals like lizardite, antigorite, and chrysotile)
Blue Apatite
Apatite (Group), Ca5(PO4)3(F,Cl,OH)
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)
Pyrite
Pyrite (Iron Disulfide), FeS2
Dendritic Agate (or Dendritic Opal)
SiO2 (for Agate), SiO2·nH2O (for Opal)
Rutilated Quartz
Quartz (SiO2) with Rutile (TiO2) inclusions
Aventurine
Aventurine Quartz (SiO2 with inclusions)
Osumilite in Granite Matrix
(K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30
Quartzite
Quartzite (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Serpentinite
Serpentinite (complex silicate of magnesium, (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)
Serpentine
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Smoky Quartz
SiO2 (Silicon Dioxide)
Quartzite (River Pebble)
Quartzite (composed primarily of Silica, SiO2)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Green Opal
Hydrated Silica (SiO2·nH2O)
Calcite
Calcite (Calcium Carbonate, CaCO3)
Quartzite Pebble
Quartzite (SiO2)
Blue Sapphire
Corundum (Al2O3) with traces of Iron and Titanium
Fuchsite (Chrome Mica)
K(Al,Cr)2(AlSi3O10)(OH)2
Basalt (Porphyritic)
Basalt (Mafic Extrusive Igneous Rock)
Fossilized Sea Urchin (Echinoid)
Echinoidea (Class); commonly Clypeasteroida for sand dollar types
Tiger's Eye
SiO2 (Pseudomorph of Quartz after Crocidolite)
Petrified Wood (Silicified Wood)
Silicified Wood / Silicon Dioxide (SiO2)
Greisen
Greisen
Quartzite River Rock
Quartzite (primarily SiO2)
Gossan (Iron Hat) with Quartz and Chlorite
Limonite/Goethite-rich Gossan (FeO(OH)·nH2O) with inclusions of Quartz and Chlorite