Linarite is a striking deep azure-blue lead-copper sulfate that forms as a secondary mineral in oxidized Pb-Cu deposits. Its color rivals azurite, but linarite is much rarer and forms thin tabular blue blades rather than azurite’s blocky crystals.
Properties
- Formula: PbCuSO4(OH)2
- Crystal system: Monoclinic
- Hardness: 2.5
- Color: Deep azure-blue to royal-blue
- Streak: Pale blue
- Luster: Sub-adamantine to vitreous
- Cleavage: Perfect on {100}
- Density: 5.3 – 5.5 g/cm³
Occurrence
Type locality: Linares (Spain). Best modern specimens: Blanchard Mine (New Mexico) — sharp azure blue blades up to 5 cm; Tsumeb (Namibia), Red Cloud Mine (Arizona) and Cornwall (UK).
Identification
Royal-blue thin tabular blades + association with Pb-Cu oxidation zone + extreme softness + reaction with acid (effervesces in HCl due to sulfate-hydroxide chemistry). Distinguish from azurite (carbonate, blockier crystals, effervesces strongly).
Collector Notes
Blanchard Mine linarite blades on quartz/galena matrix are the modern standard. Often paired with brochantite, caledonite and anglesite in display sets. Light- and air-stable, unlike many secondary minerals.
Found at these Localities
- Tsumeb Mine (楚梅布矿)
- Cornwall Mining District (康沃尔矿区)
