East African Ruby

Ruby from Mozambique (Montepuez) and Kenya (John Saul Mine) - characteristics, inclusions, and market significance.

mozambique kenya ruby corundum montepuez

Introduction

East Africa has emerged as a significant ruby source, with Mozambique's
Montepuez region now ranking among the world's major producers. Kenya's
John Saul Mine adds smaller but notable production. These sources are
filling gaps created by supply constraints from traditional origins.

Mozambican Ruby

The region's most significant ruby source:

Montepuez Region

  • Discovery: 2009
  • Location: Cabo Delgado Province, northern Mozambique
  • Operator: Gemfields (major producer) and artisanal miners
  • Significance: Now major world ruby source
  • Production: Regular auctions provide market supply

Colour Characteristics

  • Range: Strong red; some pigeon blood quality
  • Saturation: Can be excellent
  • Tone: Variable; fine medium-dark available
  • Iron content: Higher than Burmese; affects appearance

Quality Range

  • Clarity: Variable; clean stones available
  • Fluorescence: Generally moderate (iron dampens)
  • Treatment: Both heated and unheated available
  • Top quality: Competes with traditional sources

Mozambican Ruby Inclusions

Inclusion Description
Amphibole crystals Needle-like mineral inclusions
Mica platelets Reflective platy inclusions
Two-phase inclusions Liquid + gas cavities
Growth tubes Parallel channels
Colour zoning Uneven colour distribution
Silk Fine rutile needles
Apatite Small crystal inclusions

Kenyan Ruby

Quality production from East Africa's pioneer:

John Saul Mine

  • Location: Mangare area, southeastern Kenya
  • Discoverer: John Saul (American geologist)
  • Character: Fine red colour possible
  • Quality: Some comparable to Burmese
  • Production: Limited but significant

Characteristics

  • Variable quality across production
  • Some stones show strong fluorescence
  • Interesting inclusion suite
  • Growing market recognition
  • Typically smaller sizes than Mozambique

Market Position

East African ruby in the global market:

Mozambique

  • Filling gap from Burmese supply constraints
  • Transparent auctions (Gemfields) set benchmarks
  • Growing acceptance for fine stones
  • Value below Burmese but rising
  • Ethical sourcing programs available

Kenya

  • Established reputation for quality
  • Smaller market share than Mozambique
  • Collector interest for fine pieces
  • Consistent quality when available

Comparison with Burmese Ruby

Key differences from the benchmark source:

  • Fluorescence: Generally weaker due to higher iron
  • Colour character: Can match Burmese but often slightly different hue
  • Inclusions: Different suite aids origin determination
  • Price: Typically 20-50% below Burmese for comparable quality
  • Market perception: Improving as supply proves consistent

Treatment Considerations

Understanding treatment in East African ruby:

  • Heat treatment: Common; improves colour and clarity
  • Unheated premium: Fine unheated stones command premium
  • Disclosure: Expected; Gemfields material well-documented
  • Beryllium diffusion: Some material has been treated
  • Lab reports: Recommended for significant purchases