T superimposed on C or spiral?

[Jenni]

I have a pair of earrings with a hallmark I can't find info on. The earrings are a black stone(?) square with gold twisted wire accents and a silver backing and handmade ear clip.

The mark appears to be a capital T over a spiral or perhaps a C with an O inside. The earrings are marked STR14K

Any ideas? I am assuming they are American, but they might not be.
.

[JLDoggett]

It appears to be Tiffany&Co of fairly modern (C.1980's) design.
.

[Jenni]

Thank you! I was suspicious that it could be Tiffany, but could not find a mark that matched anywhere! I appreciate the assistance!
J
.

[2209patrick]

.