Sulfur (on Matrix)
Native Sulfur (S8)
mineral
Category
Synthetic Polymer (Polylactic Acid)
Browse synthetic polymer (polylactic acid) specimens identified by the Rock Identifier community.
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Limestone
Calcium Carbonate (CaCO3)
sedimentary
Jade (likely Nephrite or Jadeite)
Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (NaAlSi2O6)
Metamorphic rock (for Nephrite and some Jadeite); Mineral (for Jadeite)
Amethyst and Limestone
Amethyst (SiO2 - Silicon Dioxide) and Limestone (CaCO3 - Calcium Carbonate)
The purple specimen is a mineral (Amethyst); the white specimen is a sedimentary rock (Limestone or Marble).
Banded Calcite (Cave Onyx)
Calcium Carbonate (CaCO3)
sedimentary
Moonstone
Adularia or Orthoclase (KAlSi3O8) or Albite (NaAlSi3O8), specifically with lamellar exsolution of albite and orthoclase.
mineral
Crystal Quartz Beads (likely Clear Quartz)
Quartz (SiO₂)
Mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Milky Quartz or Calcite Pebble
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)
mineral
Granite Pebble
Granite (composed primarily of Quartz: SiO2, Feldspar: KAlSi3O8, and Mica: K(Mg,Fe)3AlSi3O10(OH)2)
igneous
Quartzite
Quartzite (SiO2)
metamorphic
Banded Calcite (Mexican Onyx)
Calcium Carbonate (CaCO3)
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartzite (Gold/Yellow)
Quartzite (SiO2)
metamorphic
Orange Calcite point
Calcite (Calcium Carbonate, CaCO3)
mineral
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Turquoise (with Hematite)
CuAl6(PO4)4(OH)8·4H2O
mineral
Limestone (with potential fossil inclusions)
Calcium Carbonate (CaCO3)
sedimentary
Limestone
Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)
sedimentary
Quartzite Pebble (with Iron Staining)
Quartzite (SiO2)
metamorphic
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Turquoise
CuAl6(PO4)4(OH)8·4H2O
mineral
Turquoise
Hydrated phosphate of copper and aluminum (CuAl6(PO4)4(OH)8·4H2O)
mineral
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Granite
Intrusive igneous rock (Acidic)
igneous
Limestone
Sedimentary rock composed of Calcium Carbonate (CaCO3)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Quartzite river stone
Quartzite (SiO2)
metamorphic
Limestone with Calcite Veining
Calcium Carbonate (CaCO3)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Quartzite (River Stone)
Quartzite (SiO2)
metamorphic
Quartzite Pebble
Metamorphic Quartzite (primarily SiO2)
metamorphic
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Pink Quartzite
Quartzite (SiO2 with iron oxide impurities)
metamorphic
Coquina
Bioclastic Limestone
sedimentary
Quartzite Pebble
Quartzite (principally SiO2)
metamorphic
Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Limestone
Calcium carbonate (CaCO3)
sedimentary