Agate
Silicon dioxide (SiO2)
mineral
Category
Organic Gemstone
Browse organic gemstone specimens identified by the Rock Identifier community.
Almandine Garnet in Matrix
Almandine Garnet (Fe3Al2(SiO4)3) in Schist/Quartz Matrix
metamorphic
Amazonite
Amazonite (KAlSi3O8)
mineral
Tektite (specifically Indochinite)
Tektite (Natural silica glass)
Mineraloid (Impact glass)
Citrine
Silicon Dioxide (SiO2)
mineral
Tiger's Eye (Golden)
Pseudomorph of Quartz after Crocidolite (SiO2 with FeOOH inclusions)
mineral
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)
mineral
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Olivine
Olivine group (Mg, Fe)2SiO4
mineral
Pyrite in Quartzite/Graphite Matrix
Iron Sulfide (FeS2)
Mineral
Black Tourmaline (Schorl)
Sodium Iron Aluminum Borosilicate (NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH)
mineral
Carnelian (Agate)
SiO2 (Silicon Dioxide with Iron Oxide impurities)
mineral
Quartz Druze (Crystalline Quartz)
Silicon Dioxide (SiO2)
mineral
Olivine Peridotite
Peridotite (comprising Olivine (Mg,Fe)2SiO4 and Pyroxene)
igneous
Olivine (Peridotite)
(Mg,Fe)2SiO4 (Magnesium Iron Silicate)
igneous
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
mineral
Citrine
Silicon Dioxide (SiO₂)
mineral
Garnet (Almandine)
Almandine, Fe3Al2Si3O12
mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Obsidian
Obsidian (Amorphous Volcanic Glass, SiO2)
igneous
Labradorite
Labradorite (a calcium-enriched feldspar mineral), (Ca, Na)(Al, Si)4O8
mineral
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2) with iron oxide impurities
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
K2 Jasper (K2 Granite)
Azurite in Granite (Al2Cu3(CO3)2(OH)2 in NaAlSi3O8)
igneous
Unakite
Epidotized Granite
metamorphic
Emerald in Matrix
Beryllium Aluminum Silicate (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Potassium Feldspar
Orthoclase (KAlSi3O8)
mineral
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
mineral
Iolite (Cordierite)
Cordierite (Magnesium Aluminum Silicate), Mg2Al4Si5O18
mineral
Red Garnet
Pyrope or Almandine (Silicate group, X3Y2(SiO4)3)
Mineral
Kimberlite
Kimberlite
igneous
Stichtite in Serpentine (Atlantisite)
Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)
metamorphic
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Mineral
Lapis Lazuli (blue bead) and Moss Agate (green heart)
Lapis Lazuli (lazurite-based rock) and Moss Agate (SiO2 with manganese/iron inclusions)
metamorphic (Lapis) and sedimentary/igneous assoc. (Moss Agate)
Unakite
Unakite (Epidotized Granite)
metamorphic
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz / Milky Quartz
Silicon Dioxide (SiO2)
mineral