Chert (Jasper/Carnelian variety)
Microcrystalline Quartz (SiO2)
Category
Browse mineral (variety of chalcedony) specimens identified by the Rock Identifier community.
Chert (Jasper/Carnelian variety)
Microcrystalline Quartz (SiO2)
Blue Quartz (Dumortierite Quartz)
Quartz (SiO2) with inclusions of Dumortierite (Al7(BO3)(SiO4)3O3)
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Granite (with alteration)
Granite (Felsic intrusive igneous rock)
Labradorite (likely Black Labradorite or Larvikite)
Labradorite (Na,Ca)(Al,Si)4O8. If a rock, it is typically anorthosite, gabbro, or norite, or a variety of syenite called Larvikite if it is specifically from Larvik, Norway.
Serpentine
Serpentinite (composed mainly of Group Minerals Antigorite, Chrysotile, and Lizardite; Mg3Si2O5(OH)4)
Obsidian
Obsidian (principally SiO2 silicon dioxide)
Banded Chert in Matrix
Microcrystalline Quartz (SiO2)
Obsidian
Volcanic glass (mainly SiO2 with inclusions)
Obsidian
Volcanic glass (SiO2 - Silicon dioxide predominant composition)
Schist
Schist
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
Red Garnet
Garnet Group (e.g., Pyrope, Almandine, Spessartine, Grossular, Andradite, Uvarovite)
Popcorn
Zea mays everta (P. Wilson) (Botanical name for the corn variety)
Kyanite (Blue and Green varieties)
Kyanite (Al₂SiO₅)
Dark-colored Igneous Rock (likely Basalt or Diabase)
Basalt (extrusive igneous) or Diabase (intrusive igneous)
Calcite
Calcite (CaCO3)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese
Banded Agate (Onyx type)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Garnet Schist
Garnet-bearing Mica Schist (variety of compositions, often Al2SiO5 with X3Y2(SiO4)3)
Clear Quartz (beads in a bracelet)
Quartz (SiO2)
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Mixed Tumbled Stones (Mostly Agate, Jasper, and Quartz)
Silicon Dioxide (SiO2)
Chert (often called Flint when dark or found in chalk)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (or Flint)
Silicon dioxide (SiO2)
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Druzy Quartz
Quartz (Silicon Dioxide, SiO2)
Pyrite
Pyrite (Iron Disulfide), FeS2
Quartzite
Quartzite (SiO2)
Rhodonite
Rhodonite (MnSiO3)
Obsidian
Obsidian (principally SiO2)
Chert (White-Tan variety)
Silicon dioxide (SiO2) / Microcrystalline Quartz
Chert (variant of Flint)
Chert (SiO2)
Rutilated Quartz
SiO2 with TiO2 inclusions
Conglomerate (Puddingstone)
Conglomerate (specifically, clastic sedimentary rock)
Gneiss
Gneiss (a metamorphic rock)
Obsidian
Volcanic Glass (comprised primarily of SiO2)
Schist (specifically Chlorite/Greenschist)
Chlorite Schist
Rough Quartz (likely Rose or Amethyst variety)
Silicon Dioxide (SiO2)
Quartz Crystal (specifically a Double-Terminated variety)
Silicon Dioxide (SiO2) - Low Quartz
Basalt (Vesicular)
Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene