Porphyritic Basalt (with Amygdales)
Amygdaloidal Porphyritic Basalt
Category
Browse mineralogical specimen specimens identified by the Rock Identifier community.
Porphyritic Basalt (with Amygdales)
Amygdaloidal Porphyritic Basalt
Quartz with Mica (likely Muscovite)
Silicon Dioxide (SiO2) with Potassium Aluminum Silicate Hydroxide Fluoride
Tiger's Eye (Tumbled Blue/Black-Golden variety)
Pseudomorph of Quartz after Crocidolite (SiO2 with Iron inclusions)
Quartz Geode
Silicon Dioxide (SiO₂)
River Rock (likely Gneiss or Quartzite)
Metamorphic rock specimen (potentially Foliated Gneiss)
Granite Water-Worn Pebble
Felsic intrusive igneous rock (Granite)
Quartz on Host Rock
Silicon Dioxide (SiO2)
Chert with Desert Varnish
Cryptocrystalline Quartz (SiO2) with Manganese/Iron oxide coating
Chert (potentially Jasper or Agatized Chert)
Microcrystalline Quartz (SiO2)
Agate
Silicon dioxide (SiO2) - variety Chalcedony
Druzy Quartz on Matrix (likely Limestone or Sandstone)
Silicon Dioxide (SiO2) with various trace impurities
Brown Quartz (Jasper or Chert)
Silicon Dioxide (SiO2)
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
Diamond
Natural Carbon (C)
Diamond (in jewelry setting)
Carbon (C)
Cubic Zirconia (in Jewelry)
Zirconium Dioxide (ZrO2)
Granite Pegmatite
Phaneritic Plutonic Igneous Rock
Granite Cobble
Granite (Phaneritic Quartz-Feldspar specimen)
Snowflake Obsidian
Volcanic Glass with Spherulite Inclusions (70-75% SiO2)
Quartz
Silicon Dioxide (SiO2)
Druzy Quartz on Agate/Chert
Silicon Dioxide (SiO2)
Siltstone Pebble
Siltstone (fine-grained siliciclastic sedimentary rock)
Chert with Epidote and Jasper inclusions
SiO2 (Silicon Dioxide) with Ca2(Al, Fe)3(SiO4)3(OH) inclusions
Quartz / Calcite Vein Rock
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Calamites Fossil (Horsetail Stem)
Calamites (Genus), part of the class Equisetopsida
Jasper with Chalcedony
Silicon Dioxide (SiO2)
Yellow Quartzite (River Pebble)
Quartzite (SiO2)
Chalcedony with Druzy Quartz Geode
Silicon Dioxide (SiO2)
Sunstone
(Ca,Na)((Al,Si)2Si2)O8 (Plagioclase Feldspar)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Amazonite
Microcline (KAlSi3O8) with lead impurities
Green Opal
Opal (Hydrated silica, SiO2·nH2O)
Citrine
Silicon Dioxide (SiO2)
Chalcedony (Desert Rose or Botryoidal Chalcedony)
Silicon Dioxide (SiO2)
Moqui Marble
Iron Oxide Concretion (Limonite/Hematite shell with Sandstone core)
Peridot
Olivine (Mg, Fe)2SiO4
Dendritic Agate or Manganese Nodule in Chert/Limestone
Silicon Dioxide (SiO2) with Manganese Oxide (MnO2) inclusions
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Conglomerate
Clastic Sedimentary Rock (Conglomerate)
Jasper Agate
Silicon dioxide (SiO2)
Quartz (Milky/Crystalline)
Silicon Dioxide (SiO2)