Spinel as an investment: the undervaluation case and honest assessment

Documented appreciation: the auction record

The appreciation of fine spinel at major auction houses is documented. Per-carat prices for the finest certified Mogok red and cobalt blue spinel have increased approximately three to five times between 2000 and 2025 at Christie's and Sotheby's Geneva. This appreciation runs ahead of the broader gem market and reflects the growing recognition described as the "spinel renaissance" (Christie's Geneva; Sotheby's Geneva published auction results; Wise, 2016).

Fine Mogok red spinel vs fine Mogok ruby: indicative per-carat price trajectory showing both appreciate but spinel remains at approximately 20–35% of equivalent ruby's per-carat price. The gap is the investment thesis, whether it closes, and how fast, is the uncertain variable. Sources: Christie's and Sotheby's Geneva.

Cobalt blue spinel: the distinct rarity tier

Cobalt blue spinel deserves separate investment treatment from red and pink spinel because its rarity is of a different order. While fine red Mogok spinel is genuinely scarce, fine cobalt blue spinel above 1 carat is among the rarest gem colours in commercial production. Sri Lanka is the primary source, production is artisanal and unpredictable, and the finest material appears at auction sporadically. When it does appear, it commands prices that can exceed fine blue sapphire on a per-carat basis (GIA; Wise, 2016; Christie's; Sotheby's).

The cobalt blue investment case does not depend on the ruby-spinel gap closing. It depends on the absolute rarity of cobalt-coloured chromophore in gem-quality spinel and the growing collector recognition of the colour's uniqueness. Unlike the red spinel investment case, which requires believing the market will eventually re-price spinel closer to ruby, the cobalt blue case requires only believing that rare colours of exceptional quality will continue to be valued by collectors. This is a lower-conviction requirement (Christie's; Sotheby's; Wise, 2016).

Entry barriers

Spinel investment entry capital is significantly more accessible than for Russian alexandrite or Kashmir sapphire, comparable to or slightly below fine tanzanite:

Fine Mogok red spinel, 2 carats, eye-clean, vivid: approximately USD 10,000–30,000 with GIA certificate.

Fine cobalt blue spinel, 1 carat, eye-clean: approximately USD 8,000–30,000 with GIA certificate.

Fine Mahenge hot pink, 2 carats, eye-clean: approximately USD 6,000–24,000 with GIA certificate.

These entry levels are meaningful for individual position sizing but not prohibitively high for serious collectors and investors who want exposure to the fine spinel appreciation story.

Honest risks

The gap may not close: The strongest risk to the spinel investment thesis is that the price gap between spinel and ruby persists indefinitely because market history and accumulated prestige are not easily repriced. Ruby's 500-year head start in royal treasuries may not be overcome in ten years or thirty. Investors who require a specific gap-closing timeline should treat this as a significant uncertainty (Christie's; Sotheby's; dealer observations).

Lower auction market depth: Spinel auction presence is growing but still smaller than ruby or sapphire. A specific stone may take longer to find its buyer at full premium pricing than comparable ruby would.

Myanmar sanctions for Mogok material: Discussed separately below. Significant risk for US-related transactions.

The Myanmar sanctions risk in detail

US sanctions on Myanmar (Burma) under the Tom Lantos Block Burmese JADE Act (2008) and subsequent executive orders prohibited the importation of Burmese ruby and jadeite into the United States. Spinel of Burmese origin falls within the scope of these sanctions for US-based buyers, dealers, and auction houses participating in US commerce. This is a significant practical constraint: Christie's and Sotheby's have New York operations, American buyers at their Geneva sales are potentially subject to US law, and dealers with US operations must carefully navigate Burma-origin inventory (US Department of Treasury OFAC; Tom Lantos Block Burmese JADE Act; Christie's and Sotheby's compliance documentation).

The sanctions situation has evolved since the 2021 military coup in Myanmar and may continue to evolve. Current legal advice from a qualified sanctions lawyer should be obtained before any significant transaction involving Burmese-origin spinel. Non-Mogok alternatives (Mahenge Tanzania, Tajikistan, Sri Lanka, Vietnam) avoid the Burma sanctions issue while providing exposure to fine spinel quality.

A realistic investment strategy for spinel

Focus on two specific tiers: fine cobalt blue from Sri Lanka (absolute rarity argument, not dependent on the ruby-spinel gap), and fine hot pink from Mahenge Tanzania (distinctive colour with its own benchmark, no Burma sanctions exposure).

For red spinel: use non-Burmese origins (Vietnam, Madagascar) if US-law exposure is a concern. If Burmese origin is acceptable and legal in your jurisdiction, Mogok red with Gübelin or AGL certification is the purest expression of the ruby-gap investment thesis.

Require GIA, AGL, or Gübelin certification with origin determination for any investment-tier purchase. The origin is the value determinant; without a certificate it is unverifiable.

Hold for minimum 10 years. The spinel renaissance is real but slower-moving than alexandrite or Kashmir sapphire appreciation. Short-term positions are disadvantaged by round-trip costs of 25–40%.

This is not investment advice. Consult a qualified financial adviser.