Glauconitic Sandstone
Glauconitic Sandstone (contains (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Category
Organic Gem Material (Botanical)
Browse organic gem material (botanical) specimens identified by the Rock Identifier community.
Chert (Mudstone)
Microcrystalline Quartz (SiO2)
sedimentary
Glauconite (Sandstone or Shale)
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
sedimentary
Pyrite in Matrix (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Chert (Basanite variety)
Microcrystalline Quartz (SiO2)
sedimentary
Fossiliferous Limestone with Brachiopod shell
Calcium carbonate (CaCO3)
sedimentary
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Chert (Jasper variation)
Silicon Dioxide (SiO2)
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Chalk
Calcium Carbonate (CaCO3)
sedimentary
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
mineral
Almandine Garnet
Almandine (Fe3Al2Si3O12)
mineral
Garnet (Red Garnet)
Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).
Mineral (specifically, a variety of the mineral species Pyrope-Almandine Garnet)
Amethyst
Amethyst (Purple Quartz); formula: SiO2 (Silicon Dioxide)
mineral
Citrine Quartz
Crystalline Silicon Dioxide (SiO2) with Ferric Iron impurities
mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Amethyst
SiO2 (Silicon Dioxide) - Purple variety of Crystalline Quartz
mineral
Amethyst (Tumbled/Weathered Quartz)
Amethyst (SiO2 with iron impurities)
mineral
Yellow Quartz (Citrine or Quartz Crystal with Iron Inclusions)
Silicon Dioxide (SiO2)
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Fire Agate (Rough)
Silicon Dioxide (SiO2) - Variety of Chalcedony
mineral
Amethyst
Quartz (Silicon Dioxide) with Ferric Iron impurities - SiO2
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Amethyst (Raw Quartz)
Silicon Dioxide (SiO2)
mineral
Sunstone
Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)
mineral
Yellow Quartz (Citrine Quartz)
Silicon Dioxide (SiO2)
mineral
Sunstone
Plagioclase Feldspar (Na, Ca)(Al, Si)4O8 with Hematite or Copper inclusions
mineral
Pearl
Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3
mineral
Fluorite
Fluorite (Calcium Fluoride - CaF2)
mineral
Red Moss Agate (Jasper)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Green Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
sedimentary
Amber
Amber (Succinite), fossilized tree resin
Mineraloid
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
sedimentary
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Tree Agate
Silicon Dioxide (SiO2) with Dendritic Inclusions
Mineral
Chert (Flint variety)
Chert (SiO2)
sedimentary
Fossiliferous Limestone
Calcareous biomicrite / Calcium Carbonate (CaCO3)
sedimentary
Chert (Smooth River Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Red Chert or Jasper)
Microcrystalline Quartz (SiO2)
sedimentary