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Inclusions

Diagnostic inclusions and fingerprinting techniques for gem identification.

Interactive Version

For detailed data tables and interactive content, visit gemmology.dev/learn/inclusions.

Types of Inclusions

Solid Inclusions

Crystals of other minerals trapped during growth.

Host Gem Common Inclusions
Ruby/Sapphire Rutile silk, zircon halos, calcite
Emerald Pyrite, calcite, tremolite, mica
Diamond Garnet, olivine, chromite

Fluid Inclusions

  • Two-phase - Liquid + gas bubble
  • Three-phase - Liquid + gas + solid crystal (diagnostic for Colombian emerald)
  • Fingerprint inclusions - Healed fractures with fluid remnants

Growth Features

  • Colour zoning
  • Growth tubes
  • Twinning
  • Phantoms

Origin Determination

Corundum by Origin

Origin Characteristic Inclusions
Burma (Ruby) Short rutile silk, calcite, swirl patterns
Kashmir (Sapphire) Tourmaline, zircon halos, milky zones
Sri Lanka Long rutile silk, hexagonal colour zoning

Emerald by Origin

Origin Characteristic Inclusions
Colombia Three-phase inclusions with halite cube
Zambia Black mica flakes, amphibole needles
Brazil Biotite mica, pyrite

Natural vs Synthetic

Natural Indicators Synthetic Indicators
Mineral inclusions Curved striae
Three-phase inclusions Gas bubbles
Fingerprint patterns Flux inclusions
Irregular zoning Chevron zoning

Data source: learn/inclusions.yaml