Granite
Phaneritic Plutonic Igneous Rock (primarily composed of quartz, alkali feldspar, and plagioclase)
igneous
Category
Mineral Based Alloy (Anthropogenic)
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Siltstone
Siltstone (composed of microscopic quartz and clay minerals)
sedimentary
Mica Schist
Mica Schist (primarily Muscovite or Biotite sheets with Quartz)
metamorphic
Biotite Mica
Biotite, K(Mg,Fe)3AlSi3O10(F,OH)2
mineral
Green Tiger's Eye
Silicified Crocidolite (Quartz variety, SiO2)
metamorphic
Granite (including Pegmatite variants)
Phaneritic Plutonic Rock (composed primarily of Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Muscovite mica)
Igneous
Sandstone with Liesegang Rings
Liesegang-banded Sandstone
sedimentary
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt (primarily SiO2, MgO, FeO, and CaO)
Igneous
Green Aura Quartz
Silicon Dioxide (SiO2) bonded with metallic vapors (typically Gold, Chromium, or Titanium)
mineral
Sandstone (lithic wacke/arenite)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Mica Schist
Mica Schist (predominantly Muscovite or Biotite sheet silicates)
metamorphic
Porphyritic Andesite
Andesite (Intermediate Extrusive Volcanic Rock)
igneous
Schist
Mica Schist (primarily composed of quartz, feldspar, and mica)
metamorphic
Sandstone
Arenite (Siliclastic sedimentary rock)
sedimentary
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
sedimentary
Shale
Shale (Consolidated fine-grained clay/silt)
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Banded Black Onyx (Chalcedony)
Silicon Dioxide (SiO₂)
mineral
Basalt
Basalt
igneous
Amygdaloidal Basalt
Vesicular-Amygdaloidal Basalt (Mafic Extrusive)
igneous
Greenstone
Metamorphosed Mafic Igneous Rock
metamorphic
Ferruginous Sandstone (Gozzan/Ironstone)
Arenite with Limonite/Goethite cement (FeO(OH)·nH2O)
sedimentary
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Basalt
Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
igneous
Mahogany Obsidian
Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)
igneous
Mica Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
metamorphic
Granite Pebble
Granite
igneous
Sandstone (lithic)
Lithic Wacke / Arenite
sedimentary
Diorite
Diorite (plutonic igneous rock)
igneous
Basalt (Black Beach Pebble)
Basalt
igneous
Alkali Basalt with iron oxidation
Mafic Volcanic Rock (Fe-bearing Basalt)
igneous
Diorite (Salt and Pepper Rock)
Diorite
igneous
Granite Pebble
Granite (Phaneritic Igneous Rock)
igneous
Mica Schist
Mica Schist (predominantly Muscovite or Biotite)
metamorphic
Schist
Mica Schist
metamorphic
Granodiorite
Granodiorite
igneous
Basalt (with possible mineral veining)
Basalt (Aphanitic Mafic Igneous Rock)
Igneous
Snowflake Obsidian
Volcanic Glass with Spherulitic Cristobalite Inclusion
igneous
Labradorite
Labradorite ((Ca,Na)(Al,Si)4O8)
mineral
Muscovite Mica (on Quartz Matrix)
Muscovite - KAl2(AlSi3O10)(OH)2
mineral