Gemstones
Spinel Buying Guide: Natural vs Lab-Grown, Prices per Carat & Quality
Red, pink, cobalt-blue and grey spinel: why collectors love it, Burmese and Tanzanian sources, lab spinel and prices per carat.
What is spinel?
Spinel is magnesium aluminium oxide; famous 'rubies' in historic crowns proved to be spinel. Hardness: 8 on the Mohs scale.
Colour and quality factors
Vivid red, hot pink ('Jedi' neon) and cobalt blue are most prized; lavender and grey are affordable.
Origins and natural (mined) stones
Myanmar (Mogok), Tanzania (Mahenge), Sri Lanka, Vietnam and Tajikistan.
Carat weight and size
Fine stones over 3 ct are uncommon; most are under 2 ct.
Prices per carat
Grey/lavender: roughly $100–$800/ct. Fine red or pink: roughly $1,500–$8,000/ct. Top Mahenge pink or cobalt blue: $10,000+/ct. These are indicative retail ranges per carat gathered from published trade and auction reporting; real prices vary widely with colour, size, origin and treatment, and are not a Riakoob quote.
Natural vs lab-grown (synthetic)
Lab spinel has been made by flame fusion for a century and costs only a few dollars per carat; it is often used as a simulant for other gems. Under US FTC guidelines a lab-made stone must be clearly described as laboratory-grown, laboratory-created or synthetic, never simply by the gem name.
Treatments you must know about
Spinel is generally untreated — one of its appeals; heating is occasionally reported. Treatment disclosure is required; ask for it in writing and on the lab report.
Certification
For significant spinel purchases, ask for a report from an independent lab such as GIA, AGL, SSEF or Gübelin stating natural or synthetic origin, any treatments and, where relevant, geographic origin.
Care and durability
Durable for daily wear.
Buyer checklist
- ✓ Report confirms natural, untreated
- ✓ Bright saturated colour
- ✓ Not a flame-fusion simulant
Verification tools & references
Every Riakoob piece arrives certified, insured and covered by our 12-month value promise.
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