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Occurs in Pinal County.

Chemical Formula: Cu3(SO4)(OH)4

Specific Gravity: 3.7-3.8

Luster: Vitreous to adamantine

Hardness: 3.5-4

Antlerite is a copper sulfate mineral that forms as a secondary mineral in the oxidized zones of copper deposits. It often appears as greenish-blue to green crystals or encrustations.

Next Pinal County mineral: Aragonite

MinDat Antlerite

Antlerite belongs to the copper sulfate mineral group. It is named after its original discovery in the Antler Mine in Arizona, USA. Antlerite is known for its vibrant blue to green-blue color and is often associated with other copper minerals in oxidized copper deposits.

Key characteristics of antlerite include:

  1. Crystal Structure: Antlerite crystallizes in the monoclinic crystal system. Its crystal structure consists of layers of copper ions linked by sulfate (SO4) groups and hydroxyl (OH) groups. This arrangement contributes to its unique color.
  2. Color and Luster: Antlerite is most well-known for its striking blue to green-blue color. The coloration is a result of copper ions in its crystal lattice. It has a vitreous (glassy) luster.
  3. Habit: Antlerite often forms as tabular or prismatic crystals, as well as in crusts or botryoidal (grape-like) aggregates. The crystal habit can vary based on the specific conditions of formation.
  4. Occurrence: Antlerite is typically found in oxidized copper deposits, often in association with other secondary copper minerals such as malachite, azurite, and chrysocolla. It forms in the weathering zone of copper ore deposits where copper-rich fluids interact with the surrounding rocks.
  5. Mineral Association: Antlerite is commonly found alongside other copper-bearing minerals, which can create visually appealing and colorful mineral assemblages. These minerals can often be identified by their vibrant colors.
  6. Geological Significance: Antlerite, along with other secondary copper minerals, provides insights into the processes of weathering, oxidation, and mineral alteration that occur within copper deposits over geological time.
  7. Collectible Mineral: Antlerite’s vivid color and relatively uncommon occurrence make it a sought-after mineral by mineral collectors and enthusiasts.