Pink Granite / K-Feldspar
Alkali feldspar granite / Potassium feldspar (Microcline/Orthoclase)
igneous
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Crinoid Stem Fossils (Indian Beads / St. Cuthbert's Beads)
Crinoid columnal ossicles (phylum Echinodermata)
fossil
Tiger Iron
Composite rock (Quartz, Tiger's Eye, Hematite, and Jasper)
metamorphic
Amethyst
Quartz (Silicon Dioxide, SiO2)
gemstone
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Quartz crystals on matrix
Silicon dioxide (SiO2)
mineral
Quartz Geode/Vug in Host Rock
SiO2 (Silicon Dioxide) in various host rocks
mineral
Green Banded Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Anthracite Coal
Anthracite
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Green Aventurine
Quartz (Silicon Dioxide, SiO2) with fuchsite inclusions
mineral
Stromatolite
Biogenic sedimentary rock / Stromatolite
sedimentary
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Granite
Intrusive Igneous Rock
igneous
Granite
Intrusive Igneous Rock
igneous
Rhyolite
Rhyolite (felsic extrusive igneous rock)
igneous
Green Aventurine
Quartz (SiO2) with fuchsite inclusions
mineral
Granite
Intrusive Igneous Rock
igneous
K-Feldspar (Microcline / Orthoclase)
Potassium Feldspar (KAlSi3O8)
mineral
Red Jasper
Silicon Dioxide (Microcrystalline Quartz), SiO2
sedimentary
Granite
Intrusive Igneous Rock (composed of quartz, alkali feldspar, and plagioclase)
igneous
Diamond and Sapphire
Carbon (Diamond, C) and Aluminum Oxide (Sapphire, Al2O3)
gemstone
Yellow Quartz
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Iceland Spar (Optical Calcite)
Calcite (CaCO3)
mineral
Basalt Pebble
Extrusive Igneous Rock
igneous
Aventurine Quartz
Quartz with fuchsite inclusions (SiO2)
mineral
Olivine Basalt (Pumice or Scoria)
Mafic extrusive igneous rock
igneous
Basalt
Extrusive Igneous Rock (Mafic)
igneous
Flint / Chert Arrowhead
Microcrystalline Quartz (SiO2)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Crinoid Fossil Fragment
Crinoidea (echinoderm fossil embedded in limestone/matrix)
fossil
Uvarovite
Ca3Cr2(SiO4)3
mineral
Jasper
Silicon Dioxide (SiO2) microcrystalline quartz variety
sedimentary
Vanadinite
Pb5(VO4)3Cl
mineral
Granite
Intrusive igneous rock
igneous
Crinoid Stem Fossil
Crinoid ossicle (phylum Echinodermata)
fossil
Lake Superior Agate
Silicon Dioxide (Chalcedony / Quartz, SiO2)
sedimentary