Satin Spar (often marketed as Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Category
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Satin Spar (often marketed as Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
River Cobble (Salt and Pepper Gneiss)
Gneiss (High-grade regional metamorphic rock)
Jasper
Jasper (Silicon Dioxide, SiO2)
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Limonite (Yellow Ochre)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
Quartzite Pebble
Quartzite (primarily SiO2)
Red Sandstone (Old Red Sandstone Pebble)
Arenite with iron oxide (Fe2O3) cement
Specular Hematite (Specularite)
Iron(III) oxide (Fe2O3)
Moonstone
Orthoclase Feldspar (KAlSi3O8) or Albite mixtures
Quartzite
Quartzite (composed primarily of Quartz, SiO2)
Chert (varietal Chalcedony or Flint)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Arkosic Sandstone
Arkose (Clastic Sedimentary Rock)
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Limonite (after Pyrite Pseudomorph)
Limonite (Hydrated Iron Oxide Mixture, FeO(OH)·nH2O)
Granite Cobble
Granite (Phaneritic Igneous Rock)
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Quartz / Quartzite
Quartzite (primarily Silicon Dioxide, SiO2)
Quartzite (River Cobble)
Metamorphic Quartz-rich Rock
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2)
Banded Agate (specifically Botswana Agate appearance)
Silicon Dioxide (SiO2)
Howlite
Howlite (Calcium borosilicate hydroxide: Ca2B5SiO9(OH)5)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
Man-made Crystal (Lead Glass)
Lead oxide-doped Silica Glass (approx. SiO2 + PbO)
Basalt
Basalt
Sandstone Pebble
Arenite (primarily Quartz, SiO2)
Grey Moonstone
Potassium Aluminum Silicate (KAlSi3O8)
Specular Hematite with Pyrite
Iron Oxide (Fe2O3) with Iron Sulfide (FeS2)
Quartzite
Quartzite (SiO2)
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Diamond (in a jewelry setting)
Cubic Carbon (C)
Orange Quartz with Epidote
Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate hydroxide (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
Quartzite
Quartzite (SiO2)
Quartz Druze (on Matrix)
Silicon Dioxide (SiO2)
Mica Schist
Schist (primarily Muscovite and Biotite mica)
Red Sandstone
Arenite (Fe2O3-rich)
Rough Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Quartzite
Quartzite (primarily SiO2)
Blue Aventurine
Silicon Dioxide (SiO2) with inclusions of Dumortierite
Limestone
Calcium Carbonate (CaCO3)