Inclusion

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Glossary Term

Inclusion

Diaspore · Zultanite
Fact-checked 2026-04-27

Pronunciation
in-KLOO-zhun

Any solid, liquid, or gaseous material trapped inside a crystal during its growth. Inclusions in gem-quality diaspore are typically minute negative crystals, two-phase fluid inclusions, and rare boehmite or chlorite needles. Inclusion type and orientation are diagnostic for natural-versus-synthetic determination and are documented in laboratory reports.