Rough Precious Opal
Hydrated Silica (SiO2·nH2O)
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Rough Precious Opal
Hydrated Silica (SiO2·nH2O)
Carnelian (Red Agate/Chalcedony)
Cryptocrystalline Quartz (SiO2) with Hematite impurities
Jasper (specifically Brecciated or Agated Jasper)
Silicon Dioxide (SiO2) - Chalcedony with impurities
Chert / Flint
Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂
Chert (White Chert/Flint)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
Magnetite
Magnetite (Fe3O4)
Calcite
Calcium Carbonate (CaCO3)
Jasper
Jasper (Silicon Dioxide, SiO2 plus various impurities)
Poppy Jasper
Jasper (variety of Chalcedony), SiO2 (Silicon Dioxide)
Chert (specifically Red Chert / Jasper nodule)
Silicon dioxide (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)
Red Jasper
Silicon Dioxide (SiO2) - variety of Chalcedony
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
Quartz (Clear Quartz)
Silicon Dioxide (SiO2)
Garnet Schist
Almandine Garnet Schist (Fe3Al2(SiO4)3 in Schistose matrix)
Quartz (Milky and Bull Quartz)
Silicon Dioxide (SiO2)
Amber
Succinite (fossilized resin)
Tree Agate (also known as Dendritic Agate)
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Amber
Succinite (fossilized tree resin)
Amber
Amber (Amorphous Organic Hydrocarbon)
Chalcedony (Yellow Jasper or Agate)
Microcrystalline Quartz (SiO2)
Ammolite
Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)
Chert (Nodule)
Silicon Dioxide (SiO2)
Mixed Gemstone Bracelet
Mixed natural minerals and rocks (e.g., Rhodonite, Malachite, Sodalite, Rose Quartz, Black Tourmaline, Quartz/Chalcedony variants)
Chert (Flint variety)
Silicon Dioxide (SiO2)
Quartz (Common or Milky)
Silicon Dioxide (SiO2)
Jasper with Iron Staining
Silicon Dioxide (SiO2) with impurities
Clear Quartz Fragment
Quartz (Silicon Dioxide, SiO2)
Red Carnelian
Carnelian (Silicon Dioxide - SiO2)
Opal
Hydrated amorphous silica (SiO2·nH2O)
Chert (often referred to as Flint or Jasper when pigmented)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Hematite
Hematite (Iron(III) oxide, Fe2O3)
Milky Quartz
Silicon Dioxide (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Dalmatian Jasper (Dalmatian Stone)
Dalmatian Stone (primarily Feldspar, Quartz, and Arfvedsonite/Tourmaline)
Dendritic Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
Jasper (specifically Polychrome or Desert Jasper)
Silicon Dioxide with impurities (SiO2)
Quartz / Milky Quartz
Quartz (Silicon Dioxide - SiO2)