Jewel of Thesia

From Memory Alpha, the free Star Trek reference

The Jewel of Thesia was an item of national heritage on the planet Straleb. Its rightful heir is Benzan who, in 2365, had the jewel smuggled to Altec, aboard the Erstwhile, to have given as a wedding proposal to Yanar, the mother of his son. (TNG: "The Outrageous Okona")