Granite Gneiss
Gneiss (Derived from Granite protolith)
metamorphic
Category
Mineral (Tectosilicate)
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Gneiss with Quartz Veining
Gneiss (High-grade metamorphic rock)
metamorphic
Gneiss
Gneiss
metamorphic
Granite Pebbles
Granite (composed primarily of Quartz SiO2, Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8), and Mica)
igneous
Nickel coin (U.S. currency)
Cupronickel (75% Copper, 25% Nickel alloy)
man-made alloy (metallic)
Schist (Greenschist / Mica Schist)
Metamorphic rock rich in platy minerals (e.g., Chlorite/Mica schist)
metamorphic
Polished orbicular granite (likely snowflake granite)
Granite, chiefly quartz, potassium feldspar, plagioclase, and dark biotite/amphibole minerals
igneous
Chrysocolla
Hydrated copper silicate - Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O
mineral
Fluorite
Calcium fluoride (CaF2)
mineral
Quartz Vein / Quartz Matrix
Silicon Dioxide (SiO2)
mineral
Fossilized Stingray Mouth Plate
Myliobatidae gen. et sp. indet. (e.g., Myliobatis, Aetobatus)
fossil
Unakite
Altered Granite (Epidotized Granite)
metamorphic
Vesicular volcanic rock, likely scoria
Scoria; composition commonly basaltic to andesitic, rich in plagioclase and pyroxene
igneous
Granite Glacial Erratic
Intrusive Phaneritic Felsic Rock (Granite)
igneous
Greenschist (Chlorite Schist)
Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)
metamorphic
Mica Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
metamorphic
Amygdaloidal Basalt
Extrusive Igneous Rock with Amygdules
igneous
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
mineral
Magnetite (Lodestone variant potential)
Magnetite (Fe3O4)
mineral
Sandstone Pebble
Arenite (SiO2 based)
sedimentary
Sandstone Pebble
Arenite (SiO2 complex)
sedimentary
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Satin Spar (Gypsum)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Satin Spar (Gypsum)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
mineral
Fluorite
Calcium fluoride (CaF2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Pegmatite (with Muscovite Mica and Quartz)
Granitic Pegmatite (chiefly KAlSi3O8, SiO2, and KAl2(AlSi3O10)(OH)2)
igneous
Blue apatite (likely rough/tumbled specimen)
Apatite group, commonly fluorapatite — Ca5(PO4)3F
mineral
Likely weathered quartz-rich rock fragment
Uncertain; possibly granitic pegmatite or quartz-bearing metamorphic rock
igneous
Fluorite
Calcium Fluoride (CaF2)
mineral
Green Aventurine and Clear Quartz Bracelet
Quartz variety with Fuchsite inclusions (Aventurine) and pure Silicon Dioxide (SiO2)
gemstone
Fluorite
Calcium Fluoride (CaF2)
mineral
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Fluorite
Fluorite (Calcium Fluoride - CaF2)
mineral
Rainbow Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Limonite (often after Pyrite)
Limonite (FeO(OH)·nH2O)
mineral
Gemstone Ring
Various (Likely Glass, Cubic Zirconia, or assorted semi-precious stones)
gemstone