2.81 Carats | Natural Cobalt Spinel - Sri Lanka (GFCO Certified)

An impressive 2.81-carat natural blue cobalt spinel from Sri Lanka, accompanied by a GFCO Gem Lab identification report confirming the gemstone as BLUE COBALT SPINEL.

The stone presents a deep, saturated blue body color with flashes of brighter cobalt, royal blue and electric cyan as light moves across its facets. Its substantial 2.81-carat weight gives the gemstone considerable presence, while the oval double-brilliant crown and step-cut pavilion create contrasting areas of deep blue and concentrated flashes of brighter color.

Cobalt blue spinel occupies a distinctive niche within the spinel family. Cobalt is associated with the highly prized blue coloration found in certain natural spinels, and laboratory documentation separating cobalt spinel from ordinary blue spinel is particularly important for collector material.

The accompanying GFCO Gem Lab report AAP95839, dated September 2, 2026, identifies the gemstone as natural spinel with the trade name Blue Cobalt Spinel. It records Sri Lankan origin, no heat – no treatment, and a strong reaction under the cobalt/chromium filter.

Gemstone: Natural Spinel
Trade Name: Blue Cobalt Spinel
Weight: 2.81 carats
Origin: Sri Lanka
Color: Blue
Shape: Oval
Dimensions: 9.30 × 7.39 × 5.51 mm
Crown Cut: Double Brilliant
Pavilion Cut: Step (3)
Treatment: No Heat – No Treatment
Cobalt/Chromium Filter: Strong Reaction
Report: GFCO Gem Lab — AAP95839
Condition: Loose Gemstone
Price: $6,000

At nearly three carats, this documented Sri Lankan cobalt spinel offers an unusual combination of size, natural blue coloration, untreated status and laboratory identification. It is equally suited to a serious colored-gem collection or as the centerpiece of a bespoke fine-jewelry design.