Honey Calcite
Calcium Carbonate (CaCO3)
Category
Browse man made object (coin) specimens identified by the Rock Identifier community.
Honey Calcite
Calcium Carbonate (CaCO3)
Chert (Field-collected Arrowhead-shaped Fragment)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossiliferous Limestone (Coquina)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Native Silver
Silver (Ag)
Chert (specifically Gray/Blue-Gray Chert)
Chert (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert (specifically Zebra Chert/Flint)
Silicon Dioxide (SiO2)
Chert (Nodule/Pebble)
Chert (Silicon Dioxide, SiO2)
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
Pyrite
Iron Disulfide (FeS2)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Larimar
Pectolite (a variety of pectolite, NaCa2Si3O8(OH))
Amethyst
SiO2 (Silicon Dioxide)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Anthracite Coal
Anthracite (high-rank coal)
Amber
Fossilized tree resin (not a true mineral as it is organic and amorphous); Chemical formula is highly variable, but often approximated as C10H16O.
Green Aventurine
Quartz (Aventurine variety) - SiO₂ with Fuchsite inclusions
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with fibrous inclusions (commonly Dumortierite)
Chalcanthite (Likely Synthetic/Lab-Grown)
Hydrated copper(II) sulfate (CuSO4·5H2O)
Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')
Silicon Dioxide (SiO2) with artificial pigment
Coral (Precious Coral)
Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).
Amazonite
Amazonite (KAlSi3O8 – a variety of Microcline, a Potassium Feldspar)
Amazonite
Amazonite (KAlSi3O8 - a variety of Microcline Feldspar)
Lapis Lazuli (Lazurite crystals on Marble)
Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]
Calcite
Calcite (CaCO3)
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Amazonite
KAlSi3O8 (Potassium Feldspar, variety of Microcline)
Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Granite
Granite (felsic intrusive igneous rock)
Rutilated Quartz
SiO2 (Quartz) with TiO2 (Rutile inclusions)
Green Aventurine
Aventurine (a variety of Quartz, SiO2 with fuchsite inclusions)
Rough Diamond
Diamond (Pure Carbon: C)
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Goldstone
Avventurina (Cu + SiO2 glass)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Jasper
Chalcedony (cryptocrystalline quartz), SiO2
Nephrite (a form of Jade)
Nephrite (a variety of the mineral actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Coal (most likely Bituminous or Anthracite)
Coal (primarily composed of carbon with varying amounts of other elements)
Tiger's Eye
Silicon dioxide (SiO2) with fibrous inclusions of crocidolite (riebeckite) that have been altered to limonite and then replaced by quartz
White Jade / White Chalcedony
Nephrite Jade (Ca2(Mg,Fe)5Si8O22(OH)2) or Chalcedony (SiO2)
Mixed Gemstone Beaded Jewelry
Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)