Garnet (likely Almandine)
Almandine (Fe3Al2(SiO4)3)
mineral
Category
Mineral, Specifically A Detrital Grain
Browse mineral, specifically a detrital grain specimens identified by the Rock Identifier community.
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
igneous
Mica Schist
Mica Schist (primarily Muscovite or Biotite Schist)
metamorphic
Sandstone (Picture Sandstone)
Arenite (primarily SiO2 with iron oxide impurities)
sedimentary
Picture Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Ironstone Concretion (Limonite/Goethite)
Iron oxide concretion (contains FeO(OH)·nH2O)
sedimentary
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
sedimentary
Quartzite with Iron Inclusions
Metamorphic Quartzite (SiO2 with Fe2O3 trace impurities)
metamorphic
Jasper and Quartzite Pebble
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary/metamorphic
Sandstone Concretion
Clastic Sedimentary Concretion (typically Quartz/Silica with Iron Oxide)
sedimentary
Carnelian
Carnelian (SiO2 - Silicon Dioxide with Hematite impurities)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Quartzite (Yellow/Iron-stained Quartz)
Quartzite (primarily SiO2 with iron oxide impurities)
metamorphic
Red Quartzite (Strawberry Quartz)
Quartzite (SiO2 with iron oxide inclusions)
metamorphic
Basalt with Epidote (Greenstone)
Epidote-bearing Metabasalt
metamorphic
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Vesicular Basalt
Vesicular Basalt (Aphanitic Mafic Igneous Rock)
igneous
Red Tiger's Eye beads
Tiger's Eye (variety of Chalcedony, SiO2)
Mineral / Gemstone (variety of Quartz)
Amygdaloidal Basalt with Quartz/Zeolite Infill
Amygdaloidal Basalt (extrusive volcanic rock with SiO2 or CaAl2Si3O10·3H2O infill)
igneous
Peridot (Olivine)
(Mg,Fe)2SiO4 (Magnesium Iron Silicate)
mineral
Porphyry (Flower Stone)
Porphyritic Basalt or Andesite
igneous
Red Sandstone (Iron-rich Sandstone)
Clastic Sedimentary Rock - Quartz Arenite / Arkose with Hematite Cement
sedimentary
Wishing Stone (Basalt with Quartz Vein)
Basalt containing a microcrystalline quartz (SiO2) or calcite vein
igneous
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Gneiss
Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)
metamorphic
Basalt
Basalt (Mafic Extrusive)
igneous
Biotite Schist
Biotite-rich Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
metamorphic
Stiped Slate Beach Pebble
Low-grade Metamorphic Slate with Quartz Vein (SiO2 on Phyllosilicate base)
metamorphic
Sandstone
Arenite (primarily composed of SiO2 - Silicon Dioxide)
sedimentary
Granite (Weathered)
Phaneritic Plutonic Rock (primarily Quartz, Feldspar, and Mica)
igneous
Ironstone (with possible Hematite/Limonite coating)
Ironstone (Fe-rich sedimentary rock)
sedimentary
Slate
Slate (foliated metamorphic rock rich in quartz, sericite, and chlorite)
metamorphic
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
sedimentary
Gold
Gold (Native Au)
mineral
Chert (specifically Gray/Tan Bedded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Yellow/Common Opal or Jasper mixture)
Silicon Dioxide (SiO2)
sedimentary
Ferruginous Quartz (Red Quartz)
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Gold Ore in Matrix
Native Gold (Au) in Quartz/Limonite host rock
mineral
White Marble (Tumbled)
Recrystallized Calcite (CaCO3)
metamorphic
Pink Granite (Gneissic Granite)
Granite (composed primarily of Quartz, K-Feldspar, and Plagioclase)
igneous