Jewel of Narvi

Description:
A gem no larger than a chestnut, cut with unparalleled skill. Its body is a deep, midnight blue, and within its heart run silver veins that shift in the light like flowing water. The jewel rests in a tiny inset cloth-lined box, crafted of cedar and silver, sealed with both Elven script and Dwarven runes.

Inscription (Elvish, along the inner lid):

"For the ring yet to be made—
To bind stone and starlight, flame and memory."

History:
This gem was gifted by Narvi to Celebrimbor in the Second Age. It was intended as the centerpiece of a ring—one that would represent the union of Dwarven endurance and Elven wisdom. It was to be a Ring of Accord and celebrate the best of both races. The ring would grant the wearer the hardiness of dwarves, the wisdom of the elves, to be used to further works of enduring beauty.

Celebrimbor never forged it.
When Sauron revealed his deception, the jewel was hidden, Narvi and Celebrimbor killed, and the peace between the dwarves and elves shattered by the deceptions of the enemy.