I think it`s silver, Cairo, fineness .800.
Compare your mark on the left with 18 K gold mark on the right.
Cairo in Arabic script is on top in both marks, the we have ‚‚800‚‚ in your mark and ‚‚18‚‚ for gold (right).
Besides, there is no ‚‚800‚‚ gold standard in Egypt.
But I would suggest to test it, very simple.