Tanzanite
Blue/Violet Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))
Category
Browse man made object (coin) specimens identified by the Rock Identifier community.
Tanzanite
Blue/Violet Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))
Cobalt Glass Slug (Man-made Glass)
Amorphous Silica with Cobalt Oxide (SiO2 + CoO)
Fired Clay Brick (Anthropic Rock substitute)
Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)
Greenstone Celt (Polished Stone Axe)
Metamorphosed mafic rock (often Basalt or Diabase)
Native Silver
Silver (elemental Ag)
Tanzanite
Blue/Violet Variety of Zoisite (Ca2Al3(SiO4)3(OH))
Gastly (Trick or Trade Halloween Series)
Cellulose-carbonaceous composite (Lignocellulose laminated with pigmentary polymers)
Nephrite Jade
Nephrite
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Undetermined Due to Blur (Possible Flesh-Tone Mineral)
Unknown (Insufficient Visual Clarity)
Petrified Wood (Silicified Fossil)
Silicified Wood (SiO2)
Orange Calcite (Banded Calcite)
Calcite (Calcium Carbonate, CaCO3)
Cullet Glass (Man-made Glass Slag)
Amorphous Silica (SiO2) with chemical additives
Granite
Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).
Man-made Green Quartz (Lab-grown or Treated)
Silicon Dioxide (SiO2) with artificial coloration
Unknown Organic Object (likely a berry or fruit)
Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Calcite
Calcite (Mineral, Calcium Carbonate - CaCO3)
Cupronickel Coin
Copper-Nickel Alloy (typically 75% Cu, 25% Ni)
Orange Calcite
Calcium Carbonate (CaCO3)
Orange Calcite point
Calcite (Calcium Carbonate, CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Amber (Copal)
Organic gemstone, fossilized tree resin (often immature amber or copal)
Green Calcite
Calcite (CaCO3)
Gold (Elemental Metal)
Gold (Au)
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Diamond (in a jewelry setting)
Diamond (Carbon, C)
Jadeite (Jade)
Jadeite, NaAlSi₂O₆
Marble
Recrystallized Calcite (CaCO3)
Orange Calcite
Calcium Carbonate (CaCO3)
Blue Calcite (commonly sold as Caribbean Calcite)
Calcium Carbonate (CaCO3)
Blue Calcite
Calcium Carbonate (CaCO3)
Orange Calcite (Mexican Onyx)
Calcium Carbonate (CaCO3)
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood / Chalcedony (SiO2)
Copper Bullion Round
Native Copper (refined), Cu
Diamond (in jewelry setting)
Diamond (C - Carbon)
Standing Liberty Quarter (Silver Specimen)
Native Silver alloy (Ag with Cu traces)
Orange Calcite
Calcium Carbonate (CaCO3)
Fluorite
Calcium Fluoride (CaF2)
Honey Calcite
Calcium Carbonate (CaCO3)
Caribbean Calcite
Calcite and Aragonite (CaCO3)