Filigree
Etymology
An altered form of the earlier "filigrane," from French, from Italian "filigrana," combining Latin filum, "thread," and granum, "grain, seed" — the tiny beads and threads of the metalwork. English reshaped the ending under the influence of "gree." The word broadened from the jeweler’s craft to any fine, lacelike intricacy.
noun · /FIL-uh-gree/
Delicate ornamental work made of fine twisted threads of gold or silver, or anything resembling it.
What it names
The lacy tracery of soldered metal wire — and, by extension, any intricate fine detailing, in prose or design — giving you a word for ornament prized for its threadlike delicacy.
Example
The reliquary was covered in silver filigree so fine it looked less forged than spun.
Related idea
Filigree is delicate openwork of twisted wire; engraving is decoration cut as lines into a solid surface.