Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Category
Organic (Geological Relative)
Browse organic (geological relative) specimens identified by the Rock Identifier community.
Slate
Metamorphosed Shale (Fine-grained Foliated Metamorphic Rock)
metamorphic
Obsidian
Volcanic Glass (70% or more SiO2)
igneous
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Scoria (Lava Rock)
Scoria
igneous
Obsidian
Volcanic Glass (SiO2)
igneous
Quartz (specifically Milky or Clear Chunk)
Silicon Dioxide (SiO2)
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Granite
Felsic Intrusive Igneous Rock
igneous
Flower Agate
Chalcedony (cryptocrystalline Quartz) with Spherulite inclusions; SiO2
mineral
Obsidian
Obsidian (Volcanic Glass)
igneous
Gold Sheen Obsidian
Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)
igneous
Quartz Crystal (specifically a small Clear Quartz point)
Silicon Dioxide (SiO2)
mineral
Scoria (Lava Rock)
Scoria (highly vesicular extrusive igneous rock)
igneous
Granite
Phaneritic Igneous Rock (composed of quartz, alkali feldspar, and plagioclase)
igneous
Desert Rose
Selenite Rose (Gypsum: CaSO4·2H2O)
mineral
Coquina
Bioclastic Limestone
sedimentary
Quartz (Milky/Clear)
Silicon Dioxide (SiO2)
mineral
Granite
Granite (phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)
igneous
Obsidian
Obsidian (Volcanic Glass, SiO2)
igneous
Jade
There are two distinct minerals commonly known as Jade: Jadeite (NaAlSi2O6) and Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2). Based on the appearance, these spheres are likely Nephrite.
Mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide) with impurities
igneous
Snowflake Obsidian
Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)
Igneous
Obsidian
Obsidian (principally SiO2)
igneous
Quartz (Milky or Iron-Stained)
Silicon Dioxide (SiO2)
mineral
Pink Granite
Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
Igneous
Slate
Foliated Metamorphic Rock (composed mainly of Quartz, Illite, and Chlorite)
metamorphic
Obsidian
Obsidian (Volcanic Glass)
igneous
Pyrite
Iron Disulfide (FeS2)
mineral
Pumice
Vesicular volcanic glass
igneous
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Coquina
Biogenic Limestone (mostly Calcium Carbonate, CaCO3)
sedimentary
Snowflake Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Obsidian
Obsidian (Volcanic Glass)
igneous
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
igneous
Gold Nugget
Native Gold (Au)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Granite
Granite (a plutonic igneous rock)
Igneous