K-Feldspar (Potassium Feldspar)
Potassium Feldspar (KAlSi3O8)
mineral
Category
Mineral Group
Browse mineral group specimens identified by the Rock Identifier community.
Learn about Mineral Group in the encyclopedia
View all →
Osumilite in Granite Matrix
(K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30
mineral
Fossil Snail
Gastropoda fossil
fossil
Moss Agate
Chalcedony with inclusions
mineral
Tumbled jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), commonly containing iron oxides and other silicates
mineral
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
mineral
Carnelian (red-orange chalcedony)
Chalcedony, cryptocrystalline SiO₂; quartz-group mineral
gemstone
Tumbled brown jasper (probable)
Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide impurities
mineral
Almandine Garnet
Almandine - Fe3Al2(SiO4)3
mineral
Small green-gray pebble (likely serpentinite)
Serpentinite, composed mainly of serpentine-group minerals
metamorphic
Polished agate or jasper nodule
Microcrystalline quartz, SiO₂, likely chalcedony with iron-oxide and other mineral inclusions
mineral
Black Tourmaline (Schorl)
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Black Tourmaline (Schorl) on Quartz
NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH)
mineral
Sodalite
Na8(Al6Si6O24)Cl2
mineral
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Almandine Garnet
Almandite (Fe3Al2(SiO4)3)
Mineral
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Sodalite (Sunset Sodalite)
Sodalite: Na8(Al6Si6O24)Cl2
mineral
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
mineral
Garnet in Matrix
Almandine Garnet (Fe3Al2(SiO4)3)
metamorphic
Biotite in Host Matrix
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
mineral
Almandine Garnet
Fe3Al2(SiO4)3
mineral
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
mineral
Serpentinite
Serpentinite (Hydrated magnesium iron silicate)
metamorphic
Bivalve Fossil (Clam Fossil)
Class Bivalvia (likely Gryphaea or similar Order)
fossil
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
mineral
Polished red gemstone beads, possibly garnet
Unconfirmed; likely almandine garnet (Fe₃Al₂(SiO₄)₃)
gemstone
Garnet in Schist
Almandine Garnet in Mica-Schist (Fe3Al2(SiO4)3)
metamorphic
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Blue Apatite
Fluorapatite / Apatite Group (Ca5(PO4)3(F,Cl,OH))
mineral
Tumbled serpentine
Serpentinite; chiefly antigorite, lizardite, and chrysotile Mg₃Si₂O₅(OH)₄
metamorphic
Chalcedony on Matrix
Silicon Dioxide (SiO2)
mineral
Clear Quartz Cluster
Silicon Dioxide (SiO2)
mineral
Stilbite
Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O)
mineral
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
mineral
Quartz with Schorl inclusions
Silicon Dioxide (SiO2) with Sodium Iron Aluminum Borosilicate Hydroxide (Black Tourmaline)
mineral
Spinosaurid Dinosaur Tooth
Spinosaurus aegyptiacus (fossilized)
fossil
Labradorite
Labradorite (Plagioclase Feldspar Series) - (Ca, Na)(Al, Si)4O8
mineral
Pistachio-green and dark mineral-bearing rock, possibly serpentine with dark inclusions
Undetermined; the image is insufficient for reliable species-level identification
metamorphic
Serpentine
Antigorite, Lizardite, and Chrysotile (Mg3Si2O5(OH)4)
metamorphic
Goniatite Fossil
Order Goniatitida
fossil
Fossilized Crinoid Stem Segment
Crinoid (Phylum Echinodermata, Class Crinoidea)
sedimentary