Many vintage eyeglass frames are marked 1/10, 12karat gold filled, others are just marked (G.F, Gold Filled). These markings are generally stamped on the temples or under the nose bridge on vintage gold-filled glasses. Sometimes silver colored frames are marked as gold-filled causing confusion to some as to the gold content of these silver tone vintage eyeglasses. (1/10 12k gold means that the frames are 10 % of 12k gold, or 5% of solid gold which is 24 karats. 1/10 12k was the most common type of gold-filled glasses). 1- Solid Gold. (1960). Such as 24 K or 21K. 2- Rolled Gold. Such as 18k.It is used for rust proof (rest resistance).                                           52          20 -    Or.  50--- 16 - The benefits of G.F eye glasses are many:         1-Strong. 2-Great quality.          3- Correction……etc.  It is consisting of (Chromium, Nickel, Iron, Copper and Zinc).  The Gold -Filled glasses for Some people are:             (Allergic, and Skin irritation and very Expensive).                    18kt solid gold eyeglass frames. Solid gold eye glasses stopped being manufactured after the rise in the price of gold in the 1970.   On some frames it was just the chassis, thefront part that held the lens Rim, while the rest of the of the frames were (Al) or Plastic. University of Al-Mustaqbal – The First and Leading Private University