K-Feldspar (Potassium Feldspar)
Potassium Feldspar (Microcline or Orthoclase), KAlSi3O8
mineral
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Pink Quartz / Rose Quartz
Silicon Dioxide (SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Pumice
Pumice (Volcanic glass / Silicic extrusive rock)
igneous
Pumice
Pumice
igneous
Brown Chert
Microcrystalline Quartz (SiO2)
sedimentary
Limestone
Calcite rock (CaCO3)
sedimentary
Chert
Microcrystalline quartz (SiO2)
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
sedimentary
Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Tumbled Quartz
Silicon Dioxide (SiO2)
mineral
Agate
Silicon dioxide (Chalcedony), SiO2
sedimentary
Fossil Shark Tooth
Chondrichthyes (Class)
fossil
Geode
Silicon Dioxide (Quartz/Chalcedony) in carbonate or volcanic host rock
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (CaCO3)
sedimentary
Geode half
Geode (often quartz/chalcedony based)
sedimentary or igneous
Limestone
Calcareous sedimentary rock (CaCO3)
sedimentary
Limestone
Sedimentary Rock (Primarily CaCO3)
sedimentary
Jasper
Microcrystalline quartz (SiO2)
sedimentary
Fossil Assortment and Geological Specimens
Various (including Ammonoidea)
fossil
Blue Sapphire
Corundum (Al2O3)
gemstone
Chert (Flint/Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Jadeite
Jadeite (NaAlSi2O6)
mineral
Green Quartzite
Metamorphic Quartz Sandstone (SiO2)
metamorphic
Amazonite
Microcline feldspar, KAlSi3O8
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Carnelian
Silicon Dioxide (Quartz variety, SiO2)
mineral
Carnelian
SiO2 (Variety of Chalcedony)
gemstone
Green Jasper
Microcrystalline Quartz (SiO2) with impurities
sedimentary
Agate
Silicon dioxide (chalcedony), SiO2
sedimentary
Flint
Silicon dioxide (Microcrystalline Quartz / SiO2)
sedimentary
Granite with Tourmaline
Felsic intrusive igneous rock containing schorl (tourmaline)
igneous
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Carnelian
Silicon Dioxide (Chalcedony variety), SiO2
mineral
White Quartz
Silicon Dioxide (SiO2)
mineral
Granite
Intrusive Igneous Rock
igneous
Elephant Skin Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Agate
Silicon dioxide (Chalcedony), SiO2
sedimentary
Sandstone
Sedimentary Rock (Quartzose Sandstone)
sedimentary
Sea Glass
Man-made vitreous material (silica-based glass)
mineral