niello
Any of various black metal alloys, made of sulphur with copper, silver or lead, used to create decorative designs on other metals.
countable, uncountable
a young woman named Renata, with a gesturing of her dark curls, beckoned him in with a cigarette-case of Russian silver and niello, which sprang open to reveal a collection of “smokes” […]
An impression on paper taken from the engraved or incised surface before the niello alloy has been inlaid.
countable, uncountable
Where it comes from
Borrowed from Italian niello, from Latin nigellus (“blackish”).
Adapted from the Wiktionary entry niello (CC BY-SA 4.0).