Weathered basaltic cobble
Altered basalt, predominantly plagioclase and pyroxene
igneous
Category
Mixed (Predominantly Sedimentary And Igneous)
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Peridotite (Olivine-bearing Xenolith)
Peridotite (predominantly Forsterite Olivine, Mg2SiO4)
igneous
Basalt with vesicles (Amygdaloidal Basalt)
Amygdaloidal Basalt (predominantly Plagioclase and Pyroxene)
igneous
Basalt
Basalt (predominantly Plagioclase Feldspar and Pyroxene)
igneous
Sandstone
Sedimentary Rock (Quartz Arenite)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Red Sandstone
Arenite (Hematitic / Ferruginous Sandstone)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Tumbled feldspar-rich stone (likely granite or pegmatite fragment)
Potassium feldspar, chiefly orthoclase or microcline (KAlSi₃O₈), possibly mixed with quartz
igneous
Rhyolitic Tuff (Breccia Type)
Rhyolitic Pyroclastic Rock (Mixed Silicates including Quartz, Feldspar, and Volcanic Glass)
igneous
Jasper (specifically Polychrome or Desert Jasper)
Silicon Dioxide (SiO2) with iron oxide and other mineral impurities
sedimentary (chemical/biological origin)
Polished chrysocolla-bearing copper mineral specimen
Chrysocolla, Cu₂H₂Si₂O₅(OH)₄·nH₂O, likely mixed with malachite and limonite/goethite
mineral
Tonsil Stone (Tonsillolith)
Calcium phosphate / Calcium carbonate biomineral
mineral
Jasper and Greenstone Pebble
Siliceous rock / Metamorphic pebble
metamorphic
Onyx (Black Onyx)
Silicon Dioxide (SiO2)
mineral
Sandstone
Sedimentary Rock (Quartz arenite)
sedimentary
Sandstone
Quartzose Sandstone (Sedimentary Rock)
sedimentary
Sapphire
Corundum (Al2O3)
gemstone
Granite
Intrusive Igneous Rock (Felsic)
igneous
Green Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Granite Boulder
Felsic Intrusive Igneous Rock
igneous
Sandstone
Quartz Arenite / Sedimentary Rock
sedimentary
Rough Gemstone Grains (Mixed Sapphires and Quartz)
Corundum (Al2O3) and Quartz (SiO2)
mineral
Amethyst
Silicon Dioxide (SiO2) with Fe3+ impurities
mineral
Snowflake Obsidian
Volcanic glass containing Spherulites (SiO2)
igneous
Green Aventurine
Aventurine Quartz (SiO2 with inclusions of Fuchsite)
mineral
Chrysocolla in Matrix
Hydrated copper silicate - (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Amethyst Geode
Silicon Dioxide (SiO2) with iron impurities
mineral
Red Sandstone
Quartz Arenite (iron-stained) / SiO2
sedimentary
Precious Opal
Hydrated silica (SiO2·nH2O)
mineraloid
Conglomerate
Conglomerate (Sedimentary Clastic Rock)
sedimentary
Coal
Anthracite / Bituminous Coal
sedimentary
Vesicular volcanic scoria (likely basaltic scoria)
Scoria; predominantly iron- and magnesium-rich silicate glass with plagioclase, pyroxene, and possible olivine
igneous
Iron-rich sulfide ore, likely pyrite-bearing gossan
Pyrite (FeS₂), possibly mixed with iron oxides/hydroxides and other sulfides
mineral
Indian Agate
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Carnelian Agate
Silicon Dioxide (SiO2) with high Iron Oxide impurities
mineral
Orbicular rhyolite (orbicular jasper-like volcanic rock)
Orbicular rhyolite; predominantly quartz, alkali feldspar, plagioclase, and volcanic glass, with concentric spherulitic growths
igneous
Decorative opal-like turtle mosaic
Likely imitation or assembled opal material; exact stones cannot be confirmed visually
gemstone
Chrysocolla in Matrix
Hydrated copper silicates (Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O))
mineral
Chrysocolla on Quartz
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) with Quartz (SiO2)
mineral
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite
metamorphic