Limestone (Flagstone)
Fossiliferous Limestone (CaCO3)
sedimentary
Category
Organic Gemstone (Often Associated With Sedimentary Sequences)
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Carnelian (Orange Agate/Chalcedony)
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Milky Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
mineral
Chrysocolla on Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Clear Quartz / Rock Crystal
Silicon Dioxide (SiO2)
mineral
Turquoise
Hydrous phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Oceanside Agate (Orbicular Agate)
Silicon Dioxide (SiO2) - Variety of Chalcedony
mineral
Hag Stone
Calcareous sedimentary rock (often Chert, Flint, or Limestone)
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Labradorite
Feldspar (variety of Anorthite), (Ca,Na)(Al,Si)4O8
mineral
Turquoise in Matrix
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
mineral
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
metamorphic
Sunstone
Oligoclase or Andesine (Feldspar Group), (Ca,Na)((Al,Si)4O8)
mineral
Unakite
Epidotized Granite
metamorphic
Carnelian Agate
Carnelian (Silicon Dioxide, SiO2)
mineral
Dalmatian Stone
Dalmatian Jasper (Aplitic Rock)
igneous
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Limonite (Ironstone Concretion)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
mineral
Pyrite
Iron Disulfide (FeS2)
Mineral
Pegmatite (with smoky quartz and tourmaline/biotite)
Pegmatitic Granite
igneous
Magnetite
Magnetite (Fe3O4)
mineral
Emerald
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Rhodonite
Rhodonite (Manganese Silicate), chemical formula: (Mn,Fe,Mg,Ca)SiO3
Mineral
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with fibrous inclusions (commonly Dumortierite)
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Amazonite
Tectosilicate (variety of Microcline), K(AlSi3O8)
mineral
Sandstone (with potential trace fossils)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
mineral
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
mineral
Blue Kyanite
Kyanite (Al2SiO5)
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
sedimentary
Banded Agate (specifically Lake Superior Agate or similar)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
sedimentary
Red Jasper
Jasper (Silicon Dioxide based crypto-crystalline Quartz with Iron inclusions)
sedimentary
Amazonite
Microcline (variety Amazonite) - K(AlSi3O8)
mineral
Ocean Jasper
Silicon Dioxide (SiO2)
Mineral_variety_of_Chalcedony
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Pyrope Garnet
Magnesium aluminum silicate (Mg3Al2Si3O12)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral