Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Category
Browse mineral (biogenic) specimens identified by the Rock Identifier community.
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Vesicular Basalt
Basalt (Mafic Extrusive Volcanic Rock)
Granite
Phaneritic Felsic Igneous Rock
Feldspar-rich Pegmatite
Granitic Pegmatite (principally KAlSi3O8)
Granite Pebble
Felsic intrusive igneous rock (composition: Quartz, Feldspar, Mica)
Quartzite with Dark Mineral Inclusions
Quartzite (primarily SiO2) with accessory minerals
Chromite
Chromite (FeCr2O4)
Gypsum (Wallboard/Drywall)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Snowflake Obsidian
Volcanic Glass with Spherulitic Cristobalite (SiO2)
Quartz Chip
Silicon Dioxide (SiO2)
Granite
Granite (Phaneritic Igneous Rock)
Granodiorite / Granite (Weathered)
Granodiorite
Sandstone
Arenite (SiO2 based with mineral cement)
Schist
Mica Schist
Epidosite (Epidote-rich rock)
Epidosite (consisting primarily of Epidote: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Greenstone / Greenschist
Greenschist facies metamorphic rock
Septarian Nodule
Septarian Concretion
Pegmatite
Granitic Pegmatite
Granite
Granite (Phaneritic Acidic Igneous Rock)
Shale or Siltstone
Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)
Green Jasper
Silicon Dioxide (SiO2) with mineral inclusions
Amygdaloidal Basalt with Quartz/Calcite Inclusions
Amygdaloidal Basalt (SiO2 / CaCO3 inclusions)
Rock Salt (Halite)
Halite (Sodium Chloride, NaCl)
Yellow Ochre (Limonite)
Limonite (FeO(OH)·nH2O)
Pyrite
Iron Disulfide (FeS2)
Quartz with inclusions
SiO2
Quartz Druzy on Matrix (likely Agate or Jasper)
Silicon Dioxide (SiO2) with various mineral inclusions
Quartz with Inclusions
Silicon Dioxide (SiO2) with various mineral inclusions
Laterite
Laterite (Ferricrete)
Quartz (Granular)
Silicon Dioxide (SiO2)
Garnet (Almandine)
Almandine Fe3Al2(SiO4)3
Amazonite
Amazonite (KAlSi3O8 - Microcline)
Green Moss Agate (Tumbled)
Silicon Dioxide (SiO2) with mineral inclusions
Quartz with Schist Matrix
Crystalline Silicon Dioxide (SiO2) in micaceous schist
Granite Pebble
Granite
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Milky Quartz
Silicon Dioxide (SiO2)
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Limonite streaks)
Sandstone (lithic)
Lithic Wacke / Arenite
Basalt (Black Beach Pebble)
Basalt
Chlorite (Small Flakes/Sand)
Chlorite Group (Magnesium Iron Aluminum Silicate Hydroxide - (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)
Granite
Granite (Alkali-feldspar granite)