Gemstone district

Madagascar Sapphire Deposits

Major modern reference population for metamorphic and basalt-related blue sapphire.

Evidence statusPublished & sourcedLast reviewed August 17, 2026
OverviewGeologyGem relationshipsSources

Evidence-backed overview

The place, clearly defined

Major modern reference population for metamorphic and basalt-related blue sapphire.

Geological context

How the occurrence is understood

Major modern reference population for metamorphic and basalt-related blue sapphire.

Bidirectional relationships

Documented gemstones

Occurrence and production are separate claims. A production label is date-bounded and does not guarantee quality, origin determination, or market value.

Major source

Sapphire

Evidence identifies the location as commercially or historically important for this gem.

Production not assessed

Occurrence is documented, but production status has not been assessed.

Evidence[1]

Evidence ledger

Sources & verification

Sources are deduplicated across the geographic record. Current-production claims receive explicit review dates; a map point never substitutes for geological or production evidence.

  1. [1]
    Aaron C. Palke, Sudarat Saeseaw, Nathan D. Renfro, Ziyin Sun, and Shane F. McClure. Geographic Origin Determination of Blue Sapphire.

    Gems & Gemology · 2019

    View authoritative source