Huebnerite Mineral Overview

• Mineral name: Huebnerite
• Mineral class: Tungstate
• Chemical formula: MnWO₄ (manganese tungstate)
• Crystal system: Monoclinic
• Mohs hardness: 4–4.5
• Color range: Brown, reddish-brown, black
• Luster: Submetallic to resinous
• Streak: Yellowish-brown
• Cleavage: Perfect (one direction)
• Fracture: Uneven
• Specific gravity: Approximately 7.1–7.3 (very heavy)
• Transparency: Opaque to translucent (thin edges)
• Common locations: United States, Peru, Bolivia, China
• Uses: Tungsten ore, collector mineral
• Similar minerals: Wolframite, scheelite

Naming and Classification

Huebnerite is a manganese-rich member of the wolframite series, named after Adolph Hübner, a German mining engineer.

It forms a solid solution series with:

• Ferberite (FeWO₄) → iron-rich
• Huebnerite (MnWO₄) → manganese-rich

Together, these are commonly referred to as:

• Wolframite group minerals

Physical and Optical Characteristics

Huebnerite typically occurs as:

• Bladed or tabular crystals
• Columnar or prismatic forms
• Massive aggregates

Its color is usually:

• Reddish-brown
• Dark brown
• Nearly black

The luster ranges from submetallic to resinous, giving it a somewhat glossy but subdued appearance.

With a Mohs hardness of 4–4.5, it is relatively soft.

Density (Key Feature)

Huebnerite is notable for:

• Very high density

It feels unusually heavy for its size due to:

• Tungsten (W) content

This is a key identification feature.

Chemical Composition and Structure

Huebnerite is composed of:

• Manganese (Mn)
• Tungsten (W)
• Oxygen (O)

It shares a structure with ferberite, forming:

• A continuous solid solution series

Formation and Geological Occurrence

Huebnerite forms in hydrothermal vein systems, particularly:

High-Temperature Veins

• Associated with granitic intrusions

Tungsten Deposits

• Found in economically important ore veins

Typical formation conditions include:

• High الحرارة
• Tungsten-rich fluids

It is commonly associated with:

• Quartz
• Cassiterite
• Scheelite
• Sulfide minerals

Common Locations

Huebnerite is found in several important regions:

• United States: Colorado, Nevada
• Peru and Bolivia: Major tungsten-producing regions
• China: Significant deposits

South American deposits are especially important for tungsten production.

Uses and Practical Significance

Huebnerite is an important source of:

Tungsten

• Used in:
  • Cutting tools
  • High-strength alloys
  • Electronics
  • Heat-resistant materials

Collector Mineral

• Attractive crystal forms
• Interest in mineral collections

Similar and Related Minerals

Huebnerite can resemble:

• Ferberite: Darker and iron-rich
• Wolframite: General term for the series
• Scheelite: Different structure and often fluoresces

Chemical testing may be needed to distinguish manganese vs. iron content.

Identification Notes for Collectors

• Look for brown to black bladed crystals
• Note high density (feels very heavy)
• Observe submetallic to resinous luster
• Check yellowish-brown streak
• Consider association with tungsten-rich veins

Huebnerite is a manganese-rich tungstate mineral, recognized for its role as a tungsten ore and its high density, making it both economically important and a distinctive mineral for collectors.