vintage crepe de chine fabric, blush pink & ivory stripe silky soft silk or poly

90s vintage 'menswear' style striped crepe de chine, blush pink and ivory. This is a 2 yard length of 45" wide fabric, in very nice condition.

The fiber is light and fluffy when teased out, very fine and so soft. Smolders on burn test - I honestly have no idea of the fiber here.

It feels like silk to me, I've never seen a polyester like this.

But I've never seen ANYTHING burn test like this. It falls in a heap of fiber but not ash, doesn't melt into a blob. And it did not ignite easily or extinguish easily, just burned the fiber (and part of my work table!) slowly.