Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Category
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Pink Opal
Hydrated Silica (SiO2·nH2O)
Fossilized Shark Tooth
Chondrichthyes (Class) fossilized tooth
Anthracite Coal
Anthracite
Chert / Flint
Microcrystalline quartz (SiO2)
Green Jasper
Microcrystalline Quartz (Chalcedony), SiO2
Pyrite
Iron Sulfide (FeS2)
Jasper
Silicon Dioxide (SiO2) with impurities
Chert / Flint Nodule
Microcrystalline Quartz (SiO2)
Chert (River Stone)
Silicon Dioxide (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Jasper
Silicon Dioxide (SiO2) with impurities
Blue Lace Agate
Silicon Dioxide (SiO2) - Chalcedony / Quartz
Limestone (specifically Dolomitic Limestone)
Calcium Magnesium Carbonate (CaMg(CO3)2)
Blue Kyanite in Schist
Al2SiO5 in Mica Schist
Glauconite (Glauconitic Sandstone)
Glauconite [(K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2]
Chert (River Pebble with Liesegang Rings)
Microcrystalline Silicon Dioxide (SiO2)
Rhodochrosite
Manganese carbonate (MnCO3)
Jasper
Microcrystalline quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Green Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Fossilized Bone
Permineralized Vertebrate Bone
Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Chert (often found as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Serpentine (Greenstone)
Antigorite, Lizardite, and Chrysolite mixture (Mg3Si2O5(OH)4)
Amber
Succiniferous fossil resin (C10H16O)
Chert (Green Chert/Jasper)
Chert (primarily Microcrystalline Quartz, SiO2)
Chert (Nodule)
Chert (composed of Microcrystalline Silica/SiO2)
Tumbled Black Jasper
Silicon Dioxide (SiO2) with iron and carbon inclusions
Amber (in Matrix/Shale)
Amber (Fossilized Tree Resin)
Rhodochrosite
Manganese carbonate (MnCO3)
Fluorite
Calcium Fluoride (CaF2)
Black Opal (Kalimaya)
Hydrated Silica (SiO2·nH2O)
Jasper
Silicon Dioxide (SiO2) with impurities
Chert (variations include Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Coquina (Fossiliferous Limestone)
Coquina (Organic Clastic Limestone)
Green Jasper / Plasma
Microcrystalline Quartz (Chalcedony), SiO2 with inclusions
Fossilized Shark Tooth (Basal Bone)
Otodus sp. (Mineralized Hydroxyapatite)
Red Jasper (Chert)
Silicon dioxide with iron inclusions (SiO2)
Petrified Wood
Silicified Wood (SiO2)