Linarite Mineral Overview
- Mineral name: Linarite
- Mineral class: Sulfate
- Chemical formula: PbCuSO₄(OH)₂ (lead copper sulfate hydroxide)
- Crystal system: Monoclinic
- Mohs hardness: 2.5–3
- Color range: Deep blue, azure blue
- Luster: Vitreous to silky
- Streak: Light blue
- Cleavage: Perfect
- Fracture: Uneven
- Specific gravity: Approximately 5.3–5.5 (heavy)
- Transparency: Transparent to translucent
- Common locations: Germany, England, United States, Greece
- Uses: Collector mineral
- Similar minerals: Azurite, brochantite, chalcanthite
Naming and Classification
Linarite is a lead copper sulfate mineral, named after Linares, Spain, though it is more famously associated with classic European localities.
It is part of a group of secondary sulfate minerals that form in the oxidation zones of metal-rich deposits.
Physical and Optical Characteristics
Linarite typically occurs as:
- Elongated prismatic crystals
- Radiating clusters
- Crusts and coatings
Its most striking feature is its intense deep blue color, often described as:
- Rich azure
- Sapphire-like blue
The luster is vitreous, sometimes silky in fibrous forms, giving it a bright and attractive appearance.
With a Mohs hardness of 2.5–3, it is soft and fragile.
Color (Key Feature)
Linarite is especially prized for:
- One of the deepest blue colors among minerals
This color is due to:
- Copper (Cu) in its structure
It is often compared to azurite but can appear even more vivid in well-formed crystals.
Chemical Composition and Structure
Linarite is composed of:
- Lead (Pb)
- Copper (Cu)
- Sulfate (SO₄)
- Hydroxyl (OH)
It forms through chemical reactions involving:
- Copper and lead minerals
- Sulfate-rich solutions
Formation and Geological Occurrence
Linarite forms as a secondary mineral in oxidized zones of lead-copper deposits, particularly:
Oxidation Zones
- Weathering of primary sulfide minerals
Typical formation conditions include:
- Near-surface environments
- Oxidizing conditions
- Presence of sulfate-bearing fluids
It is commonly associated with:
- Anglesite
- Cerussite
- Brochantite
- Azurite
Common Locations
Linarite is found in several classic and modern localities:
- Germany: Linares and other historic deposits
- England: Cornwall (classic specimens)
- United States: Arizona, Utah
- Greece: Lavrion
English and Greek specimens are especially prized by collectors.
Uses and Practical Significance
Linarite has no industrial use due to its rarity and softness.
It is highly valued for:
Collector Mineral
- Exceptional blue color
- Attractive crystal forms
Safety Considerations
Linarite contains lead, so:
- Avoid inhaling dust
- Do not ingest
- Wash hands after handling
Display specimens are generally safe when handled properly.
Similar and Related Minerals
Linarite can resemble:
- Azurite: More common, often forms larger masses
- Brochantite: Green rather than blue
- Chalcanthite: Softer and more water-soluble
The deep blue color and crystal habit help distinguish linarite.
Identification Notes for Collectors
- Look for deep blue prismatic crystals
- Note softness (2.5–3)
- Observe vitreous luster
- Check high density (feels heavy)
- Consider association with lead and copper minerals
Linarite is a lead copper sulfate mineral, recognized for its intense azure-blue color and striking crystal forms, making it one of the most visually captivating minerals for collectors.