Dolomite
Dolomite (CaMg(CO3)2)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Dolomite
Dolomite (CaMg(CO3)2)
Granitic Gneiss
Gneiss (High-grade metamorphic rock)
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
Pyrite (on Shale/Matrix)
Iron Disulfide (FeS2)
Kyanite (Blue or Blue-Grey)
Kyanite (Al2SiO5)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Green Aventurine
Silicon dioxide (SiO2) with Fuchsite inclusions
Iron-stained Quartz Pebble
Crystalline Silicon Dioxide (SiO2) with Hematite/Limonite staining
Quartz (Microcrystalline/Gravel)
Silicon Dioxide (SiO2)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Quartz pebble
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Quartz (Smoky/Grey Quartz Variant)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz / Quartzite Fragment
Silicon Dioxide (SiO2)
Quartz / Quartzite Pebble
Silicon Dioxide (SiO2)
Quartz (Common or Milky Quartz)
Silicon Dioxide (SiO2)
Quartz with Chlorite or Hornblende inclusions
Silicon dioxide (SiO2) with phyllosilicate or amphibole inclusions
Blue Apatite
Apatite (Group), Ca5(PO4)3(F,Cl,OH)
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Green Quartz (Prasiolite/Adventurine)
Silicon Dioxide (SiO2) with inclusions
Howlite
Howlite (Calcium Borosilicate Hydroxide: Ca2B5SiO9(OH)5)
Gold Nugget
Native Gold (Au)
Quartz Geode
Silicon Dioxide (SiO2) in a Secondary Formation
Fluorite
Calcium Fluoride (CaF2)
Geode (Unopened)
Silicon Dioxide (SiO2) in sedimentary vugs
Quartz pebble
Silicon Dioxide (SiO2)
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Amethyst
Quartz variety; SiO2 (Silicon Dioxide)
Azurite-Malachite with Limonite
Cu3(CO3)2(OH)2 (Azurite) / Cu2CO3(OH)2 (Malachite)
Limonite Concretion
Limonite (FeO(OH)·nH2O)
Fuchsite (Chrome Mica)
Cr-bearing Muscovite - K(Al,Cr)2(AlSi3O10)(OH)2
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
Fluorite
Calcium Fluoride (CaF2)
Pyrite
Iron Sulfide (FeS2)
Sandstone (Graywacke)
Clastic Sedimentary Rock (Lithic Sandstone)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Glauconite (Green Sandstone)
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
Dyed Quartz Geode
Silicon Dioxide (SiO2) with artificial pigment
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Lepidolite
K(Li,Al)3(Si,Al)4O10(F,OH)2
Yellow Jade (often Serpentine or Dolomite)
Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.