Quartz
Silicon Dioxide (SiO2)
mineral
Category
Igneous, Sedimentary, Metamorphic, Mineral, Gemstone, Fossil, Or Meteorite
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Ironstone Concretion (Limonite/Goethite)
Ferruginous Sandstone / Ironstone (FeO(OH)·nH2O)
sedimentary
Peridot (Olivine)
Olivine (Magnesium Iron Silicate), (Mg,Fe)2SiO4
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
mineral
Feldspar (specifically Orthoclase or Plagioclase)
Potassium Aluminum Silicate (KAlSi3O8) or Sodium/Calcium Aluminum Silicate
mineral
Clear Quartz
SiO2 (Silicon Dioxide)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Crystalline Silicon Dioxide (SiO2)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Weathered sandstone pebble
Quartz-rich sandstone, commonly arkose or lithic sandstone
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Olivine in Basalt (Peridotite Xenolith)
Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt
igneous
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
gemstone
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Massive White Quartz
Silicon Dioxide (SiO2)
mineral
Garnet (Almandine variety)
Almandine Garnet (Fe3Al2(SiO4)3)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Quartz Fragment
Silicon Dioxide (SiO2)
mineral
Fossil shell or shell fragment
Likely a calcareous bivalve or gastropod fragment; precise identification requires locality and microscopy
fossil
Small weathered mineral/rock fragment
Indeterminate; possibly quartz-bearing feldspathic rock or calcite-rich specimen
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (SiO2)
mineral
Quartz (Milky/Gray variety)
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Peridot
Forsterite-Fayalite (Olivine group), (Mg,Fe)2SiO4
gemstone
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Sandy Ironstone
Ferruginous Sandstone
sedimentary
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Likely rough amber
Amber (fossilized tree resin; composition varies, commonly dominated by polymerized terpenoids)
gemstone
Rounded brown pebble, likely weathered sandstone or iron-stained quartzite
Probable quartz-rich sandstone (SiO₂-dominated); exact identification requires testing
sedimentary
Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
mineral
Olivine in Basalt matrix
Peridotite (Mg, Fe)2SiO4
igneous
Quartz (Small Fragment)
Silicon Dioxide (SiO2)
mineral