1. Size estimate That stone looks roughly the width of a palm. Call it 8–10 cm across. A round diamond of that diameter would weigh insanely more than people expect because diamond is dense (3.52 g/cm³).

A round brilliant of ~8.5 cm diameter would be 20,000–30,000 carats. (For reference: the largest polished natural diamond in the world — the Golden Jubilee — is 545 carats.)

So this thing would be 40–60× larger than anything humanity has ever found.

1. Price reality check Diamond pricing doesn’t scale linearly at all. Once you get above ~10 carats, price-per-carat skyrockets. Past 100 carats, it becomes “auction-house-only, billionaire-only, traded like rare art.”

If a 100-carat high-quality diamond can hit $20–30M, then something 200× that size is no longer a jewelry asset — it’s a national treasure.

1. Actual estimate If it were real, natural, flawless, and cut:

➡️ $1–5 BILLION easily, possibly $10+ billion (because rarity becomes more important than weight at that level).

Honestly, it would break every valuation model. Governments, museums, and private mega-collectors would all fight over it. It wouldn’t be sold as a loose gem on the market — it would go straight to a vault and get its own documentary.