Limonite pseudomorph after pyrite
Goethite / Limonite pseudomorph after Pyrite (Fe3+O(OH) replacing FeS2)
mineral
Category
Minerals
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Granitic Gneiss
Gneiss (Complex silicate composition)
metamorphic
Jade (likely Jadeite or Nephrite)
Jadeite (NaAlSi2O6) or Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)
Mineral/Mineraloid
Pegmatite with mica and feldspar
Granitic pegmatite; chiefly quartz (SiO₂), feldspar, and mica, possibly with tourmaline or sulfides
igneous
Petrified Wood / Fossilized Wood
Silicified Wood (Silicon Dioxide - SiO2)
fossil
River Stone / Pebble
Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)
Mineral, Sediment
Quartz with Iron Staining
Silicon Dioxide (SiO2)
mineral
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive volcanic rock)
igneous
Copper-bearing Quartz Vein in Host Rock
Quartz with Malachite/Chrysocolla staining
igneous/metamorphic with mineral
Nephrite Jade
Nephrite
Mineral/Rock
Kidney Stone
Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)
mineral
Quartz with Inclusions
Silicon Dioxide (SiO2)
mineral
Granodiorite
Granodiorite (containing Plagioclase, Quartz, and K-feldspar)
igneous
Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Mineral Sand (Heavy Mineral Sand Concentrate)
Placer deposit concentrate containing minerals such as ilmenite, rutile, zircon, and magnetite
mineral
Gneiss
Gneiss
metamorphic
Serpentinite (likely)
Serpentinite; predominantly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and relic olivine/pyroxene
metamorphic
Shale
Shale (clastic sedimentary rock)
Sedimentary
Green Quartz
Silicon Dioxide (SiO2)
mineral
Granitic gneiss or weathered granite cobble
Quartz–feldspar–mica rock; likely gneiss (compositionally granite-derived)
metamorphic
Gneiss
High-grade metamorphic rock (Gneiss)
metamorphic
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
mineral
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
sedimentary
River Cobble (likely Basalt or Greenstone)
Mafic Igneous Rock (with possible chloritic alteration)
igneous
Petrified Wood
Silicified Wood (SiO2)
fossil
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
sedimentary
Basalt with Epidote/Chlorite
Amygdaloidal Basalt (SiO2 with (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)))
igneous
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Quartz Crystal Matrix
Silicon Dioxide (SiO2)
mineral
Weathered vesicular volcanic rock, likely basaltic scoria
Vesicular basalt/scoria; chiefly plagioclase, pyroxene, olivine, and volcanic glass
igneous
Rounded green-gray pebble, likely serpentinite or altered basalt
Probable serpentinite (hydrated ultramafic rock) or greenstone; image insufficient for certain identification
igneous
Quartz Pebble
Silicon dioxide (SiO2)
sedimentary
Weathered green-gray stone, likely serpentinite or chlorite-rich metamorphic rock
Probable serpentinite (antigorite–lizardite), possibly chlorite schist or altered basalt
metamorphic
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
mineral
Bumblebee Jasper
Anhydrite-Aragonite mixture with Orpiment and Realgar
mineraloid
Gneiss (Metamorphic Cobble)
Gneiss
metamorphic
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Indigo Gabbro
Gabbro (MaFIC intrusive rock)
igneous