Mineral Based Human Made Alloy

Sandstone Cobble

Clastic Sedimentary (Sandstone)

Sandstone (River Cobble)

Clastic sedimentary rock (primarily SiO2 with various lithic fragments)

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic volcanic rock with secondary mineral fillings)

Basalt

Extrusive Mafic Igneous Rock

Chert Nodule

Microcrystalline Silica (SiO2)

Biotite Schist

Biotite Mica Schist [K(Mg,Fe)3AlSi3O10(OH,F)2]

Lepidolite on Pegmatite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Granular Sandstone

Arenite (variable composition, primarily SiO2)

Basalt

Basalt (composition of plagioclase, pyroxene, and olivine)

Sandstone (Ferruginous)

Arenite (complex silicate composition with iron oxides)

Sandstone

Arenite (composed primarily of SiO2)

Muscovite

Muscovite (KAl2(AlSi3O10)(OH)2)

Fuchsite

K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Basalt with Quartz Vein and Weathering Crust

Amygdaloidal or Porphyritic Basalt

Vesicular Basalt (Iron-rich)

Scoriaceous Basalt / Oxidized Vesicular Basalt

Andesite

Intermediate Volcanic Rock (Andesite)

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

Mica Schist

Mica Schist (predominantly Muscovite or Biotite sheet silicates)

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3 iron oxide staining)

Basalt (Crushed Stone Aggregate)

Mafic Volcanic Basalt (Major Minerals: Plagioclase Feldspar, Pyroxene, Olivine)

Granite

Phaneritic Felsic Igneous Rock (Granite)

Snowflake Obsidian

Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)

Granite

Phaneritic Plutonic Igneous Rock (composed of Quartz, Feldspar, and Mica)

Muscovite Mica

Muscovite (Potassium Mica) KAl2(AlSi3O10)(OH)2

Biotite on Matrix

Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)

Chert Nodule in Limestone

Chert (Microcrystalline Quartz, SiO2) and Limestone (Calcium Carbonate, CaCO3)

Orbicular Jasper (Ocean Jasper variant)

Silicon Dioxide (SiO2) with iron oxide inclusions

Selenite

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Dendritic Agate (also known as Dendritic Siltstone or Mudstone)

Silicon Dioxide with Manganese/Iron Oxide inclusions (SiO2 + MnO2)

Biotite Mica in Host Rock

Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)

Moss Agate

Chalcedony (Silicon Dioxide / SiO2)

Labradorite

Labradorite ((Ca,Na)(Al,Si)4O8)

Granite (Micro-specimen)

Plutonic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Sandstone (likely with Borings or Vesicular Basalt)

Clastic Sedimentary Rock (Sandstone)

Sandstone (Ferruginous)

Ferruginous Sandstone (SiO2 with Fe2O3/FeO(OH) cement)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide - SiO2)

Bull Quartz (White Quartz)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (Fe-bearing Clastic Sedimentary Rock)

Fuchsite (Green Muscovite in Quartz)

K(Al,Cr)2(AlSi3O10)(OH)2 - Chromium-rich Muscovite