Linarite: Properties and Occurrences

Linarite is a somewhat rare, crystalline mineral that is known among mineral collectors for its unusually intense, pure blue color. It is known for its exceptionally bright blue color. It is formed by the oxidation of galena and chalcopyrite and other copper sulfides. It is a combined copper lead sulfate hydroxide with formula PbCuSO4(OH)2.

This beautiful and somewhat rare mineral is usually found as crusts of small crystals. Linarite crystals are highly attractive to collectors and highly collectible. It was first identified in 1822. It is named after the Linares Plateau, Spain.

General Information

  • Category: Sulfate minerals
  • Formula: PbCu[(OH)2|SO4]
  • Crystal system: Monoclinic
  • Crystal class: Prismatic (2/m) (same H-M symbol)
  • Color: Deep azure blue.

Fig: Linarite

Properties

Linarite is a minor ore of copper where it exists in large copper deposits. It has a Mohs hardness of 2.5 and a specific gravity of 5.3 – 5.5. Linarite is formed from the oxidation of lead and copper minerals such as galena and chalcopyrite. The color is impressive for the tiny sparkling crystals. The blue color of linarite is magnificent, and it is a pity that large facetable rough has not been found.

  • Crystal habit: Crystals elongated and tabular; in crusts and aggregates
  • Twinning: Common on {100}, also on {001}
  • Cleavage: Perfect on {100}, imperfect on {001}
  • Fracture: Conchoidal
  • Mohs scale hardness: 2.5
  • Luster: Sub-adamantine, vitreous
  • Streak: Pale blue
  • Diaphaneity: Transparent, translucent
  • Specific gravity: 5.3 – 5.5
  • Optical properties: Biaxial (-)

Occurrence: Secondary mineral in the oxidized zones of lead-copper deposits.

Linarite occurs as monoclinic prismatic to tabular crystals and irregular masses. One of the most famous occurrences of this mineral is the Blanchard Mine in Bingham, Socorro Co., New Mexico. It is easily confused with azurite but does not react with dilute hydrochloric acid as azurite does. It occurs in association with brochantite, anglesite, caledonite, leadhillite, cerussite, malachite and hemimorphite.

Association: Brochantite, anglesite, caledonite, leadhillite, cerussite, malachite, hemimorphite

 

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