Biotite / Black Mica
K(Mg,Fe)3(AlSi3O10)(F,OH)2
Category
Browse mineral like biological tissue specimens identified by the Rock Identifier community.
Biotite / Black Mica
K(Mg,Fe)3(AlSi3O10)(F,OH)2
Dendritic Agate or Tree Agate
Silicon Dioxide (SiO2) with impurities of manganese or iron oxide
Rutilated Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2 with Epidote/Tourmaline inclusions
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Sandstone (Graywacke)
Clastic Sedimentary Rock (Lithic Sandstone)
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)
Schist
Mica Schist
Granite
Granite
Granite Pebble
Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)
Scoria with Calcite Infills
Vesicular Basalt with secondary Calcification (CaCO3)
Blue Quartz
Quartz (SiO2) with inclusions
Drupa Quartz (Sparkly Drusy Quartz on Matrix)
Crystalline Silicon Dioxide (SiO2) on host rock
Sandstone
Arenite (SiO2 based)
Quartz (Granular Milky Quartz fragment)
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Fluorite
Calcium fluoride (CaF2)
Chalcopyrite
Chalcopyrite (CuFeS2)
Bauxite
AlOx(OH)3-2x (mixture of Gibbsite, Boehmite, and Diaspore)
Amygdaloidal Basalt with Quartz/Calcite Inclusions
Amygdaloidal Basalt (SiO2 / CaCO3 inclusions)
Granite
Phaneritic Igneous Rock (Granite)
Obsidian
Volcanic Glass (SiO2)
Mahogany Obsidian
Volcanic glass containing Magnetite/Hematite
Rutilated Quartz
Silicon Dioxide (SiO2) with Titanium Dioxide (TiO2) inclusions
Opal
Hydrated silica (SiO2·nH2O)
Quartz Geode (with Agate banding)
Silicon Dioxide (SiO2)
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
Ferruginous Sandstone
Arenite with Iron-oxide cement
Clear Quartz
Silicon Dioxide (SiO2)
Serpentine Jade (New Jade/Olive Jade)
Serpentinite (a rock composed primarily of serpentine minerals) / Mg3Si2O5(OH)4 for Antigorite and Lizardite
Malachite
Copper carbonate hydroxide [Cu2CO3(OH)2]
Potassium Feldspar and Quartz
KAlSi3O8 (Potassium Feldspar) and SiO2 (Quartz)
Sandstone
Arenite (primarily SiO2)
Chert with Quartz/Calcite Vein
Microcrystalline Silica (SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Laterite
Laterite (Ferricrete)
Rose Quartz
Quartz (Silicon Dioxide - SiO2)
Chert / Flint
Cryptocrystalline quartz (SiO2)
Quartz Druse (on Chalcedony/Agate base)
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)