Mica / Muscovite or Biotite
Phyllosilicate mineral group (e.g., KAl2(AlSi3O10)(OH)2)
Category
Browse igneous and mineral specimens identified by the Rock Identifier community.
Mica / Muscovite or Biotite
Phyllosilicate mineral group (e.g., KAl2(AlSi3O10)(OH)2)
Amygdaloidal Basalt
Extrusive Igneous Rock with Amygdules
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
Biotite or Phlogopite Mica
K(Mg,Fe)3(AlSi3O10)(F,OH)2
Granite
Intrusive Igneous Rock
Diorite
Intrusive Igneous Diorite
K2 Jasper (K2 Granite)
Azurite in Granite (Al2Cu3(CO3)2(OH)2 in NaAlSi3O8)
Epidote in Matrix
Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
Sodalite
Na8(Al6Si6O24)Cl2 (Sodium Aluminum Silicate Chloride)
Black Obsidian
Volcanic glass
Magnetite (Loadstone candidate)
Iron(II,III) oxide (Fe3O4)
Weathered granite or granitic gneiss
Granite; chiefly quartz, feldspar, and mica, possibly with gneissic foliation
Dalmatian Stone
Dalmatian Jasper (a misnomer for an Aplite with Arfvedsonite spots)
Granite
Granite (a common igneous rock)
Milky Quartz
Silicon Dioxide (SiO2)
Likely quartz-bearing rock or mineral fragment
Indeterminate; possibly quartz (SiO₂) with iron-oxide staining and darker matrix
Magnetite / Iron Ore
Magnetite (Fe3O4)
Granite
Granite (Felsic intrusive igneous rock)
Feldspar
Feldspar (Orthoclase/Microcline)
Clear Quartz
Silicon Dioxide (SiO2)
Natural Gemstone Cabochons (Ruby, Moonstone, Emerald, Citrine)
Ruby (Al2O3:Cr), Moonstone (KAlSi3O8), Emerald (Be3Al2(SiO3)6:Cr), Citrine (SiO2)
Educational Geologic Collection
Mixed Mineral and Rock Collection (Various compositions)
Obsidian
Extrusive igneous volcanic glass
Granite
Felsic intrusive igneous rock
Granite
Felsic Plutonic Igneous Rock
Raw Corundum (Sapphire/Ruby variant)
Aluminum oxide (Al2O3)
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Pyrite in Matrix
Iron Sulfide (FeS2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Pyrite (Tumbled)
Iron Disulfide (FeS2)
Prehnite
Calcium aluminum silicate hydroxide, Ca2Al(AlSi3O10)(OH)2
Quartz (Milky / Clear Quartz Fragment)
Silicon Dioxide (SiO2)
White Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Pyrite
Iron sulfide (FeS2)
Yellow Aventurine
Quartz (Silicon Dioxide, SiO2) with inclusions
Chalcopyrite (Peacock Ore)
Chalcopyrite (CuFeS2)
Eudialyte in Matrix
Eudialyte [Na15Ca6(Fe,Mn)3Zr3(Si25O73)(O,OH,H2O)3(Cl,OH)2]
Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Pyrite
Iron Disulfide (FeS2)