Fossiliferous Limestone (containing Brachiopods)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Category
Browse organic gemstone specimens identified by the Rock Identifier community.
Fossiliferous Limestone (containing Brachiopods)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Chert (Black Chert/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossil Coral (Favosites)
Favosites (Order: Tabulata, Phylum: Cnidaria)
Petrified Wood
Silicified Wood (SiO2)
Slate
Slate (Foliated metamorphic rock)
Emerald in Matrix
Emerald (Beryllium Aluminum Silicate), Be3Al2(SiO3)6
Turquoise
Hydrate phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Diamond (faceted)
Carbon (C)
Diamond / Clear Quartz / Glass paste
Carbon (Diamond) / Silicon Dioxide (Quartz)
Green Beryl (Emerald variety)
Beryllium aluminum silicate (Be3Al2Si6O18) with Chromium/Vanadium impurities
Amethyst (Druzy Quartz)
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Turquoise (Dyed Howlite or Magnesite imitation)
Hydrated phosphate of copper and aluminum / CuAl6(PO4)4(OH)8·4H2O
Jasper
Silicon Dioxide (SiO2)
Black Sapphire
Corundum (Al2O3)
Blue Quartzite (Dyed)
Metamorphosed Quartz-rich Sandstone (SiO2 with organic dye)
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and organic impurities
Dyed Blue Agate (Dragon Vein Agate)
Silicon Dioxide (SiO2) with artificial cobalt/organic dyes
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.
Shark Tooth Fossil
Otodus sp. (possibly Cretalamna)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Banded Chert (or River Jasper)
Microcrystalline Quartz (SiO2) with iron oxide impurities
Chert (variously identified as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Field Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Anthracite Coal
Anthracite
Septarian Nodule (Thunder Egg)
Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Tan/Grey variety)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Limestone-hosted Pebble)
Sedimentary Cryptocrystalline Quartz (SiO2)
Chert (often called Flint or Jasper locally)
Chert (Microcrystalline Quartz, Formula: SiO2)
Petrified Wood
Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)
Sunstone (Feldspar)
(Ca,Na)((Al,Si)2Si2O8) with inclusions of Hematite or Goethite
Turquoise in Matrix
Hydrous phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Banded Agate (Lake Superior Agate style)
Cryptocrystalline Quartz (SiO2)
Healer's Gold (Pyrite and Magnetite in Schist)
Magnetite (Fe3O4) and Pyrite (FeS2) in Mica Schist
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Amazonite
Potassium Feldspar (KAlSi3O8)
Banded Agate (Gray Agate)
Silicon Dioxide (SiO2) - Chalcedony