Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
mineral
Category
Sedimentary (Secondary Mineral) Within Igneous
Browse sedimentary (secondary mineral) within igneous specimens identified by the Rock Identifier community.
Quartz
Quartz (SiO₂)
Mineral
Snowflake Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Milky Quartz
Quartz (SiO2)
Mineral
Chert (with Quartz vein/coating)
Microcrystalline Quartz (SiO2)
sedimentary
Garnet (likely Almandine or a blend)
Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.
Mineral
Ironstone Concretions (Ironstone)
Ferruginous Sandstone or Siltstone (Fe2O3)
sedimentary
Pegmatite with Schorl (Black Tourmaline) and Mica
Pegmatite (complex association of NaAlSi3O8, NaFe3Al6(BO3)3Si6O18(OH)4, and KAl2(AlSi3O10)(OH,F)2)
igneous
Blue Sapphire (in a faceted jewelry setting)
Corundum (Al2O3) with trace Iron and Titanium
mineral
Black Pearl (Tahitian Type)
Aragonite / Conchiolin composite (CaCO3)
mineraloid
Red Jasper (Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Septarian Nodule
Septarian Concretion
sedimentary
Labradorite
Labradorite (a calcium-enriched feldspar mineral), (Ca, Na)(Al, Si)4O8
mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Amazonite
K(AlSi3O8), Microcline
mineral
Native Sulfur
Sulfur (S8)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Sandstone with Quartz Veins
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary
Chert (specifically Flint or Jasper variant)
Silicon Dioxide (SiO2)
sedimentary
Gold Placer (Gold Flakes and Nuggets)
Native Gold (Au)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Smoky Quartz (with complementary stones in jewelry setting)
Smoky Quartz (Silicon Dioxide - SiO2)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace Titanium, Manganese, or Iron
mineral
Smoky Quartz
Smoky Quartz (SiO2: Silicon Dioxide)
mineral
Gneiss (Metamorphic Rock)
Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)
metamorphic
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
mineral
Chert (Flint Nodular)
Chert (Silicon dioxide, SiO2)
sedimentary
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Quartz (Smoky/Grey variety)
Silicon Dioxide (SiO2)
mineral
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Calcite on Limestone (or Fossil)
Calcium Carbonate (CaCO3)
sedimentary
Amethyst
Silicon Dioxide (SiO2) with trivalent iron (Fe3+) impurities
mineral
Strawberry Quartz
Silicon Dioxide (SiO2) with Hematite or Goethite inclusions
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
mineral
Peridot in Basalt
Olivine ((Mg, Fe)2SiO4) in Basalt
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Sunstone
Oligoclase (Plagioclase Feldspar) - (Na,Ca)(Si,Al)4O8 with Hematite or Copper inclusions
mineral