Basalt
Basalt (Mafic Extrusive Igneous Rock)
Category
Browse mineral based composite specimens identified by the Rock Identifier community.
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Sandstone (Cross-bedded Drill Core)
Clastic Sedimentary Rock (primarily SiO2)
Basalt (Greenstone)
Amygdaloidal Basalt / Chloritized Basalt
Slag
Anthropogenic glassy silicate
African Turquoise
Teal Jasper (Macro-crystalline Quartz/Sio2 + Inclusions of Copper, Iron, and Manganese)
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Gabbro
Gabbro (Coarse-grained Mafic Igneous Rock)
Marble
Metamorphosed Limestone (main mineral: Calcite, CaCO3)
Diorite (with Iron Staining)
Phaneritic Intermediate Igneous Rock
Mica-rich schist, likely lepidolite or muscovite schist
Mica schist; predominantly muscovite KAl₂(AlSi₃O₁₀)(OH)₂, possibly lithium-rich lepidolite
Biotite Schist
Biotite-rich Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
Basalt
Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 with (Ca,Na)(Al,Si)4O8
Schist (Micaceous Schist)
Micaceous schist (Mainly Muscovite/Biotite mixed with Quartz)
Garnet-Mica Schist
Garnetiferous Porphyroblastic Schist
Diorite
Diorite (Intermediate intrusive igneous rock)
Opalite
Synthetic Glass, SiO2 base with metallic inclusions
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Basalt
Basalt
Extrusive mafic igneous rock
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
Pink Granite
Phaneritic Felsic Igneous Rock (high K-feldspar)
Conglomerate
Conglomeratic Sandstone / Polymictic Conglomerate
Banded Gneiss
Gneiss (Metamorphic Rock)
Granite cobble
Granite
Biotite Schist
Biotite Schist
Granite
Phaneritic Intrusive Igneous Rock (primarily Quartz, Feldspar, and Mica)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz - SiO2)
Chert (Iron-stained)
Silicon Dioxide (SiO2)
Chert (and Flint)
Silicon Dioxide (SiO2)
Basalt with Desert Varnish
Mafic Volcanic Rock (Fe/Mg rich Silicate)
Basalt with Scoria/Vesicular Texture
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Basalt
Mafic volcanic rock, primarily composed of Plagioclase, Pyroxene, and Olivine
Basalt
Extrusive mafic igneous rock
Andesite
Andesite (Intermediate Extrusive Volcanic Rock)
Lepidolite Bracelet
Lepidolite (K(Li,Al)3(Si,Al)4O10(F,OH)2) often in Quartz matrix
Basalt
Extrusive mafic igneous rock
Granite
Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase Feldspar)
Labradorite
Labradorite (a variety of Plagioclase Feldspar), Na(AlSi3O8) to Ca(Al2Si2O8)
Basalt
Extrusive Mafic Igneous Rock
Beryl (Variety Mix)
Be3Al2(Si6O18)
Howlite
Ca2B5SiO9(OH)5
Citrine
Silicon Dioxide (SiO2) with iron impurities