Frame material of rimless eyeglasses!

[glasses store]

I have been wearing eyeglasses for years, and I love frameless style most, because they can be fitted with high index lenses and good AR-coatings which look invisible when worn. But the quality of frame material is really important, I know that titanium is a great choice, but have you ever heard that a quality rimless eyeglass may contain very thin gold or silver wire frame? What does this mean?