Pumice
Pumicite (Amorphous glass with varying chemical composition, often rhyolitic)
Category
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Pumice
Pumicite (Amorphous glass with varying chemical composition, often rhyolitic)
Dendritic Opal (Merlinite)
Hydrated Silica with Manganese/Iron oxide inclusions (SiO2·nH2O)
Amazonite
Microcline (variety Amazonite), K(AlSi3O8)
Amber
Succinite (specifically for Baltic amber); chemical formula approximately C10H16O
Chert (specifically Flint Arrowhead)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Chert (specifically as a lithic artifact/projectile point)
Chert (Silicon dioxide, SiO2)
Blue Banded Agate (Dyed)
Silicon Dioxide (SiO2) - Chalcedony variety
Yellow Quartz or Citrine
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide with iron impurities), SiO2
Granite
Granite (a common term for a felsic intrusive igneous rock)
Petrified Wood
Silicified Wood (primarily SiO₂)
Carnelian
Carnelian (Silicon Dioxide, SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with ferric impurities)
Pyrite
Iron Sulfide (FeS2)
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron oxide inclusions)
Amazonite
Potassium Feldspar (Microcline), K(AlSi3O8)
Green Quartz (Prasiolite variant or Aventurine)
Silicon Dioxide (SiO2)
Amethyst
Amethyst (variety of Quartz, SiO2)
Amethyst (Quartz Cluster)
Silicon Dioxide (SiO2) with iron impurities
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Carnelian
Silicon Dioxide (SiO2) - variety of Chalcedony
Yellow Calcite
Calcium Carbonate (CaCO3)
Citrine
Silicon Dioxide (SiO2) with iron impurities
Chalcedony (Agate/Chert variety)
Silicon Dioxide (SiO₂)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with impurities of iron)
Chalcedony (Common Opal or Agate variant)
Silicon Dioxide (SiO₂)
Chert (Yellow or Tan Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2
Naga Silver-Inlaid Ebony and Bone/Horn Beads
Diospyros (Ebony) or Keratin (Horn) with Silver/White-Metal Inlay
Chert (Pink Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Amazonite
Amazonite (KAlSi3O8, a variety of Microcline)
Carnelian
Carnelian (a variety of Chalcedony), SiO2 (Silicon Dioxide)
Amethyst (as seen in jewelry)
Amethyst (Silicon Dioxide SiO2 + Fe4+)
Sunstone
Plagioclase Feldspar (Na,Ca)(Al,Si)4O8
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (or Flint)
Chert (microcrystalline or cryptocrystalline quartz, SiO2)
Moonstone
Orthoclase Feldspar (KAlSi3O8) or Albite mixtures
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2