NauglamirThe Nauglamir - The Dwarves aided Finrod in the building of Nargothrond and were rewarded well for their labor.  In turn, the Dwarves made for Finrod the Nauglamir.

 

"...for Finrod had brought more treasures out of Tirion than any other of the princes of the Noldor.  And in that time was made for him the Nauglamir, the Necklace of the Dwarves, most renowned of their works in the Eldar Days.  It was a carcanet of gold, and set therein were gems uncounted from Valinor, but it had a power within it so that it rested lightly on its wearer as a strand of flax, and whatsoever neck it clasped it sat always with grace and loveliness" ~The Silmarillion, chap. 13 (Of the Return of the Noldor)

 

This necklace would play a crucial role between the Dwarves and the Sindar at the end of the First Age (see Thingol Slain & Alliance Broken)