Chert / Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Category
Organic (Often Found By Beachcombers)
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Aragonite / Calcite Geode
Calcium Carbonate (CaCO3)
mineral
Granite (with Orthoclase and Quartz)
Phaneritic Felsic Igneous Rock (KAlSi3O8 + SiO2)
igneous
Pink Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
mineral
Granite
Granitoid
igneous
Pyrite in Shale
Iron Sulfide (FeS2)
mineral
Azurite and Malachite on Matrix
Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2CO3(OH)2
mineral
River Cobble (Conglomerate context)
Unconsolidated Fluvial Alluvium (comprised of various lithologies like Quartzite, Granite, or Basalt)
sedimentary
Unakite
Epidotized Granite (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) and KAlSi3O8)
metamorphic
Yellow Calcite (Banded Calcite)
Calcium Carbonate (CaCO3)
mineral
Turquoise in Matrix
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
mineral
Honey Calcite
Calcium Carbonate (CaCO3)
mineral
Lapis Lazuli
Lapis Lazuli (Complex silicate mixture)
metamorphic
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
igneous
Malachite
Copper carbonate hydroxide, Cu2CO3(OH)2
mineral
Quartz Crystal
Silicon Dioxide (SiO2)
mineral
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
mineral
Purple Banded Agate
Cryptocrystalline Quartz (SiO2)
mineral
Fossilized Brachiopod
Brachiopoda (Class Rhynchonellata or Spiriferida)
sedimentary
Honey Calcite
Calcium Carbonate (CaCO3)
mineral
Kidney Stone (Renal Calculus)
Calcium oxalate monohydrate (Whewellite) / CaC2O4·H2O
mineral
Rhodonite
Manganese Inosilicate (MnSiO3), often with Ca, Fe, Mg, Zn
Mineral
Yellow Quartz or Citrine
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Serpentinite
Serpentinite (composed primarily of mineral group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4)
metamorphic
Iron Meteorite (Campo del Cielo)
Iron Meteorite, Group IAB (FeNi Alloy: Kamacite and Taenite)
igneous
Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Chrysocolla on Quartz
Chrysocolla (Cu2−xAlx(H2−xSi2O5)(OH)4·nH2O) often associated with Quartz (SiO2)
mineral
Almandine Garnet
Fe3Al2(SiO4)3
mineral
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (Goethite)
sedimentary
Chrysocolla
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4 nH2O
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Red Jasper with Quartz and Hematite
Silicon Dioxide (SiO2) with Ferric Iron inclusions
sedimentary
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
mineral
Quartz Vein with Iron Staining
Silicon Dioxide (SiO2) with limonite/hematite staining
mineral
Septarian Nodule Segment (Commonly known as Dragon Stone or Lightning Stone)
Septarian Nodule (CaCO3 / Hydrated Calcium Carbonate)
sedimentary
Amazonite
Amazonstone (KAlSi3O8)
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Gneiss (Banded Gneiss)
Gneiss
metamorphic
Sandstone (Ferruginous)
Sandstone (SiO2 with iron oxide inclusions)
sedimentary
Siltstone with iron staining
Siltstone (primarily SiO2 with FeO(OH) coatings)
sedimentary
Green Tourmaline
Elbaite (part of Tourmaline group), Na(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4
mineral